Refactor caret positioning

core/pom.xml

@@ -50,7 +50,13 @@
 			<artifactId>flow-nbt</artifactId>
 			<version>1.0.1-SNAPSHOT</version>
 		</dependency>
-	</dependencies>
+        <dependency>
+            <groupId>org.jetbrains</groupId>
+            <artifactId>annotations</artifactId>
+            <version>RELEASE</version>
+            <scope>compile</scope>
+        </dependency>
+    </dependencies>
 
 	<build>
 		<plugins>

core/src/main/java/it/cavallium/warppi/gui/expression/Caret.java

@@ -1,23 +1,28 @@
 package it.cavallium.warppi.gui.expression;
 
+import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
+import it.cavallium.warppi.gui.expression.blocks.BlockOrContainer;
+import it.cavallium.warppi.gui.expression.blocks.BlockPosition;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import java.util.Arrays;
 
 public class Caret {
 
-	private int pos;
+	@NotNull
-	private int remaining;
+	private BlockPosition pos;
 	private CaretState state;
 	private final int[] lastSize;
 	private final int[] lastLocation;
 
-	public Caret(final CaretState state, final int pos) {
+	public Caret(final CaretState state, final BlockPosition pos) {
 		this(state, pos, new int[] { 0, 0 }, new int[] { 2, 5 });
 	}
 
-	public Caret(final CaretState state, final int pos, final int[] lastLocation, final int[] lastSize) {
+	public Caret(final CaretState state, final @NotNull BlockPosition pos, final int[] lastLocation, final int[] lastSize) {
 		this.state = state;
 		this.pos = pos;
-		remaining = pos;
 		this.lastLocation = lastLocation;
 		this.lastSize = lastSize;
 	}
@@ -26,26 +31,27 @@ public class Caret {
 	 * Copy
 	 * @param old
 	 */
-	public Caret(Caret old) {
+	public Caret(Caret old, BlockContainer newRoot) {
-		this.pos = old.pos;
+		this.pos = clonePosition(old.pos, newRoot);
-		this.remaining = old.remaining;
 		this.state = old.state;
 		this.lastSize = Arrays.copyOf(old.lastSize, old.lastSize.length);
 		this.lastLocation = Arrays.copyOf(old.lastLocation, old.lastLocation.length);
 	}
 
-	public void skip(final int i) {
+	private BlockPosition clonePosition(BlockPosition pos, BlockContainer newRoot) {
-		remaining -= i;
+		BlockOrContainer el = newRoot;
+		var url = pos.getURL();
+		for (int i : url) {
+			el = el.getAt(i);
+		}
+		return new BlockPosition(el);
 	}
 
-	public int getPosition() {
+	@NotNull
+	public BlockPosition getPos() {
 		return pos;
 	}
 
-	public int getRemaining() {
-		return remaining;
-	}
-
 	public CaretState getState() {
 		return state;
 	}
@@ -64,12 +70,8 @@ public class Caret {
 		}
 	}
 
-	public void setPosition(final int i) {
+	public void setPosition(final BlockPosition pos) {
-		pos = i;
+		this.pos = pos;
-	}
-
-	public void resetRemaining() {
-		remaining = pos;
 	}
 
 	public void setLastLocation(final int x, final int y) {
@@ -90,4 +92,7 @@ public class Caret {
 		return new int[] { lastSize[0], lastSize[1] };
 	}
 
+	public boolean isHere(BlockOrContainer pos) {
+		return getPos().get() == pos;
+	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/ExtraMenu.java

@@ -5,6 +5,7 @@ import java.util.Arrays;
 import it.cavallium.warppi.device.display.DisplayOutputDevice;
 import it.cavallium.warppi.event.KeyboardEventListener;
 import it.cavallium.warppi.gui.expression.blocks.Block;
+import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockVariable;
 import it.cavallium.warppi.gui.expression.blocks.TreeContainer;
 import it.cavallium.warppi.gui.graphicengine.Renderer;
@@ -46,7 +47,7 @@ public abstract class ExtraMenu<T extends Block> implements KeyboardEventListene
 		return false;
 	}
 
-	public abstract ExtraMenu<T> clone(final TreeContainer parent, InputContext ic);
+	public abstract ExtraMenu<T> clone(final BlockContainer parent, InputContext ic);
 
 	public abstract ExtraMenu<T> clone(T newBlockVariable);
 

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/Block.java

@@ -11,13 +11,13 @@ import it.cavallium.warppi.math.parser.features.interfaces.Feature;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
-public abstract class Block implements TreeBlock, GraphicalElement {
+public abstract class Block implements TreeBlock, BlockOrContainer, GraphicalElement {
 
 	protected boolean small;
 	protected int width;
 	protected int height;
 	protected int line;
-	protected TreeContainer parent;
+	protected BlockContainer parent;
 	
 	public Block() {
 		
@@ -27,7 +27,7 @@ public abstract class Block implements TreeBlock, GraphicalElement {
 	 * Copy
 	 * @param b
 	 */
-	public Block(TreeContainer parent, Block b) {
+	public Block(BlockContainer parent, Block b) {
 		this.small = b.small;
 		this.width = b.width;
 		this.height = b.height;
@@ -43,15 +43,10 @@ public abstract class Block implements TreeBlock, GraphicalElement {
 	 *            Position relative to the window.
 	 * @param y
 	 *            Position relative to the window.
-	 * @param small
 	 */
 	public abstract void draw(DisplayOutputDevice ge, Renderer r, int x, int y, Caret caret);
 
-	public abstract boolean appendBlock(Caret caret, Block newBlock, boolean splitAdjacent);
+	public abstract boolean appendBlock(Caret caret, Block newBlock);
-
-	public abstract boolean deleteBlock(Caret caret);
-
-	public abstract BlockReference<?> getBlock(Caret caret);
 	
 	/**
 	 * Used only to get inner blocks when deleting the parent block.
@@ -64,8 +59,6 @@ public abstract class Block implements TreeBlock, GraphicalElement {
 	@Override
 	public abstract void recomputeDimensions();
 
-	public abstract int computeCaretMaxBound();
-
 	@Override
 	public int getWidth() {
 		return width;
@@ -81,10 +74,6 @@ public abstract class Block implements TreeBlock, GraphicalElement {
 		return line;
 	}
 
-	public int getCaretDeltaPositionAfterCreation() {
-		return 1;
-	}
-
 	public boolean isSmall() {
 		return small;
 	}
@@ -98,18 +87,66 @@ public abstract class Block implements TreeBlock, GraphicalElement {
 	public abstract Feature toFeature(MathContext context) throws Error;
 
 	@Override
-	public TreeContainer getParentContainer() {
+	public BlockContainer getParentContainer() {
 		return parent;
 	}
 
+	@Override
+	public BlockContainer getParent() {
+		return parent;
+	}
+
+	@Override
+	public BlockOrContainer getAt(int index) {
+		var ic = getInnerContainers();
+		return ic.get(index);
+	}
+
+	@Override
+	public int getIndex() {
+		return parent != null ? parent.getContentUnsafe().indexOf(this) : -1;
+	}
+
 	@Override
 	public boolean hasParent() {
 		return parent != null;
 	}
 
-	public void setParent(final TreeContainer parent) {
+	public void setParent(final BlockContainer parent) {
 		this.parent = parent;
 	}
 	
-	public abstract Block clone(TreeContainer parent, InputContext ic);
+	public abstract Block clone(BlockContainer parent, InputContext ic);
+
+	public BlockReference<?> getReference() {
+		if (this.hasParent()) {
+			return this.parent.getReference(this);
+		} else {
+			return null;
+		}
+	}
+
+	public BlockPosition getLastInnerPosition() {
+		var innerContainers = getInnerContainers();
+		if (innerContainers != null && !innerContainers.isEmpty()) {
+			var lastContainer = innerContainers.get(innerContainers.size() - 1);
+			var content = lastContainer.getContent();
+			if (content.isEmpty()) {
+				return new BlockPosition(lastContainer);
+			} else {
+				return new BlockPosition(content.get(content.size() - 1));
+			}
+		} else {
+			return null;
+		}
+	}
+
+	public BlockPosition getFirstInnerPosition() {
+		var innerContainers = getInnerContainers();
+		if (innerContainers != null && !innerContainers.isEmpty()) {
+			return new BlockPosition(innerContainers.get(0));
+		} else {
+			return null;
+		}
+	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockChar.java

@@ -23,7 +23,7 @@ public class BlockChar extends Block {
 	 * @param b
 	 * @param ic
 	 */
-	protected BlockChar(final TreeContainer parent, final BlockChar b, InputContext ic) {
+	protected BlockChar(final BlockContainer parent, final BlockChar b, InputContext ic) {
 		super(parent, b);
 		this.ch = b.ch;
 	}
@@ -36,20 +36,10 @@ public class BlockChar extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		return false;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		return false;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return null;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		width = BlockContainer.getDefaultCharWidth(small) - 1;
@@ -67,11 +57,6 @@ public class BlockChar extends Block {
 		return ch;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return 0;
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) {
 		return new FeatureChar(getChar());
@@ -88,7 +73,7 @@ public class BlockChar extends Block {
 	}
 
 	@Override
-	public BlockChar clone(final TreeContainer parent, InputContext ic) {
+	public BlockChar clone(final BlockContainer parent, InputContext ic) {
 		return new BlockChar(parent, this, ic);
 	}
 

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockContainer.java

@@ -15,9 +15,8 @@ import it.cavallium.warppi.math.parser.features.interfaces.Feature;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
-import it.unimi.dsi.fastutil.objects.ObjectListIterator;
 
-public class BlockContainer implements TreeContainer, GraphicalElement {
+public class BlockContainer implements TreeContainer, BlockOrContainer, GraphicalElement {
 
 	private static boolean initialized = false;
 
@@ -30,39 +29,39 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 	private int line;
 	public final boolean withBorder;
 	private boolean autoMinimums;
-	private final TreeBlock parent;
+	private final Block parent;
 
 	public BlockContainer() {
 		this(null, false, BlockContainer.getDefaultCharWidth(false), BlockContainer.getDefaultCharHeight(false), true);
 		autoMinimums = true;
 	}
 
-	public BlockContainer(final TreeBlock parent) {
+	public BlockContainer(final Block parent) {
 		this(parent, false, BlockContainer.getDefaultCharWidth(false), BlockContainer.getDefaultCharHeight(false), true);
 		autoMinimums = true;
 	}
 
-	public BlockContainer(final TreeBlock parent, final boolean small) {
+	public BlockContainer(final Block parent, final boolean small) {
 		this(parent, small, BlockContainer.getDefaultCharWidth(small), BlockContainer.getDefaultCharHeight(small), true);
 		autoMinimums = true;
 	}
 
-	public BlockContainer(final TreeBlock parent, final boolean small, final ObjectArrayList<Block> content) {
+	public BlockContainer(final Block parent, final boolean small, final ObjectArrayList<Block> content) {
 		this(parent, small, BlockContainer.getDefaultCharWidth(small), BlockContainer.getDefaultCharHeight(small), content, true);
 		autoMinimums = true;
 	}
 
-	public BlockContainer(final TreeBlock parent, final boolean small, final boolean withBorder) {
+	public BlockContainer(final Block parent, final boolean small, final boolean withBorder) {
 		this(parent, small, BlockContainer.getDefaultCharWidth(small), BlockContainer.getDefaultCharHeight(small), withBorder);
 		autoMinimums = true;
 	}
 
-	public BlockContainer(final TreeBlock parent, final boolean small, final int minWidth, final int minHeight, final boolean withBorder) {
+	public BlockContainer(final Block parent, final boolean small, final int minWidth, final int minHeight, final boolean withBorder) {
 		this(parent, small, minWidth, minHeight, new ObjectArrayList<>(), withBorder);
 		autoMinimums = false;
 	}
 
-	public BlockContainer(final TreeBlock parent, final boolean small, final int minWidth, final int minHeight, final ObjectArrayList<Block> content, final boolean withBorder) {
+	public BlockContainer(final Block parent, final boolean small, final int minWidth, final int minHeight, final ObjectArrayList<Block> content, final boolean withBorder) {
 		this.parent = parent;
 		this.small = small;
 		this.minWidth = minWidth;
@@ -77,7 +76,7 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 		recomputeDimensions();
 	}
 
-	private BlockContainer(final TreeBlock parent, BlockContainer old, InputContext ic) {
+	private BlockContainer(final Block parent, BlockContainer old, InputContext ic) {
 		this.autoMinimums = old.autoMinimums;
 		this.content = new ObjectArrayList<>();
 		for (Block b : old.content) {
@@ -94,15 +93,30 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 		this.withBorder = old.withBorder;
 	}
 	
-	public BlockContainer clone(final TreeBlock parent, InputContext ic) {
+	public BlockContainer clone(final Block parent, InputContext ic) {
 		return new BlockContainer(parent, this, ic);
 	}
 
 	@Override
-	public TreeBlock getParentBlock() {
+	public Block getParentBlock() {
 		return parent;
 	}
 
+	@Override
+	public Block getParent() {
+		return parent;
+	}
+
+	@Override
+	public BlockOrContainer getAt(int index) {
+		return content.get(index);
+	}
+
+	@Override
+	public int getIndex() {
+		return parent != null ? parent.getInnerContainers().indexOf(this) : -1;
+	}
+
 	@Override
 	public boolean hasParent() {
 		return parent != null;
@@ -155,7 +169,7 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 
 	public BlockReference<?> getBlockAt(final int i) {
 		final Block b = content.get(i);
-		return new BlockReference<>(b, i, this);
+		return new BlockReference<>(b, i, content, this);
 	}
 
 	public int getSize() {
@@ -183,7 +197,7 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 	public void draw(final DisplayOutputDevice ge, final Renderer r, final int x, final int y, final Caret caret) {
 		int paddingX = 1;
 
-		if (caret.getRemaining() == 0) {
+		if (caret.isHere(this)) {
 			if (content.size() > 0) {
 				BlockContainer.drawCaret(ge, r, caret, small, x, y + line - content.get(0).line, content.get(0).height);
 			} else {
@@ -199,113 +213,39 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 			r.glDrawLine(x + paddingX, y + height - 1, x + paddingX + width - 1, y + height - 1);
 		} else {
 			for (final Block b : content) {
-				caret.skip(1);
 				b.draw(ge, r, x + paddingX, y + line - b.line, caret);
 				paddingX += b.getWidth();
-				if (caret.getRemaining() == 0) {
+				if (caret.isHere(b)) {
 					BlockContainer.drawCaret(ge, r, caret, small, x + paddingX, y + line - b.line, b.height);
 				}
 				paddingX += 1;
 			}
 		}
-		caret.skip(1);
 	}
 
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
 
-		if (caret.getRemaining() == 0) {
+		if (caret.isHere(this)) {
 			addBlock(0, newBlock);
 			added = true;
 		}
 
 		int pos = 0;
 		for (final Block b : content) {
-			caret.skip(1);
 			pos++;
-			added = added | b.appendBlock(caret, newBlock, splitAdjacent);
+			added = added | b.appendBlock(caret, newBlock);
-			if (caret.getRemaining() == 0) {
+			if (caret.isHere(b)) {
 				addBlock(pos, newBlock);
 				added = true;
 			}
 		}
-		caret.skip(1);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-
-		int pos = 0;
-		for (final Block b : content) {
-			caret.skip(1);
-			pos++;
-			final int deltaCaret = caret.getRemaining();
-			final int caretOldPos = caret.getPosition();
-			removed = removed | b.deleteBlock(caret);
-			if (caret.getRemaining() == 0 || removed == false && deltaCaret >= 0 && caret.getRemaining() < 0) {
-				ObjectArrayList<Block> blocks = this.getBlockAt(pos - 1).get().getInnerBlocks();
-				ObjectArrayList<BlockContainer> innerContainers = this.getBlockAt(pos - 1).get().getInnerContainers();
-				int innerContainersBeforeCaret = 0;
-				int currentBlockIndex = 0;
-				if (innerContainers != null) {
-					for (BlockContainer c : innerContainers) {
-						currentBlockIndex += c.computeCaretMaxBound();
-						if (currentBlockIndex > deltaCaret) {
-							break;
-						}
-						innerContainersBeforeCaret++;
-					}
-				}
-				// If the caret is at the end of a block with inner containers don't delete anything and enter into that block.
-				if (innerContainers == null || (innerContainers.size() - innerContainersBeforeCaret != 0)) {
-					removeAt(pos - 1);
-					if (blocks != null) {
-						ObjectListIterator<Block> blocksIterator = blocks.iterator();
-						int blockNum = 0;
-						while (blocksIterator.hasNext()) {
-							Block block = blocksIterator.next();
-							addBlockUnsafe(pos - 1 + blockNum, block);
-							blockNum++;
-						}
-					}
-					caret.setPosition(caretOldPos - innerContainersBeforeCaret);
-					removed = true;
-				}
-			}
-		}
-		caret.skip(1);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	public BlockReference<?> getBlock(final Caret caret) {
-		BlockReference<?> block = null;
-
-		int pos = 0;
-		for (final Block b : content) {
-			caret.skip(1);
-			pos++;
-			final int deltaCaret = caret.getRemaining();
-
-			block = b.getBlock(caret);
-			if (block != null) {
-				return block;
-			}
-			if (caret.getRemaining() == 0 || deltaCaret >= 0 && caret.getRemaining() < 0) {
-				block = getBlockAt(pos - 1);
-				return block;
-			}
-		}
-		caret.skip(1);
-		return block;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		int l = 0; //Line
@@ -430,14 +370,6 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 		}
 	}
 
-	public int computeCaretMaxBound() {
-		int maxpos = 0;
-		for (final Block b : content) {
-			maxpos += 1 + b.computeCaretMaxBound();
-		}
-		return maxpos + 1;
-	}
-
 	public Function toFunction(final MathContext context) throws Error {
 		final ObjectArrayList<Block> blocks = getContent();
 		final ObjectArrayList<Feature> blockFeatures = new ObjectArrayList<>();
@@ -454,4 +386,22 @@ public class BlockContainer implements TreeContainer, GraphicalElement {
 		return result;
 	}
 
+	public <T extends Block> BlockReference<T> getReference(T block) {
+		var i = content.indexOf(block);
+		if (i < 0) return null;
+		return new BlockReference<>(block, i, content, this);
+	}
+
+	public ObjectArrayList<Block> getContentUnsafe() {
+		return content;
+	}
+
+	public Block getLastBlock() {
+		return content.isEmpty() ? null : content.get(content.size() - 1);
+	}
+
+	public BlockPosition getLastPosition() {
+		var lastBlock = getLastBlock();
+		return lastBlock != null ? new BlockPosition(lastBlock) : new BlockPosition(this);
+	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockDivision.java

@@ -19,14 +19,19 @@ public class BlockDivision extends Block {
 	private int paddingLeftUpper;
 	private int paddingLeftLower;
 	private int h1;
+	private ObjectArrayList<BlockContainer> innerContainers;
 
 	public BlockDivision() {
 		containerUp = new BlockContainer(this, false);
 		containerDown = new BlockContainer(this, false);
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(2);
+		innerContainers.add(containerUp);
+		innerContainers.add(containerDown);
 	}
 
-	private BlockDivision(final TreeContainer parent, BlockDivision old, InputContext ic) {
+	private BlockDivision(final BlockContainer parent, BlockDivision old, InputContext ic) {
 		super(parent, old);
 		containerUp = old.containerUp.clone(this, ic);
 		containerDown = old.containerDown.clone(this, ic);
@@ -34,6 +39,10 @@ public class BlockDivision extends Block {
 		paddingLeftUpper = old.paddingLeftUpper;
 		h1 = old.h1;
 		System.out.println(String.join(",", ""+h1, ""+old.h1, ""+line, ""+old.line));
+
+		innerContainers = new ObjectArrayList<>(2);
+		innerContainers.add(containerUp);
+		innerContainers.add(containerDown);
 	}
 
 	@Override
@@ -47,38 +56,16 @@ public class BlockDivision extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerUp.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerUp.appendBlock(caret, newBlock);
-		added = added | containerDown.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerDown.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-		removed = removed | containerUp.deleteBlock(caret);
-		removed = removed | containerDown.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		BlockReference<?> bl = null;
-		bl = containerUp.getBlock(caret);
-		if (bl != null) {
-			return bl;
-		}
-		bl = containerDown.getBlock(caret);
-		return bl;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		final int w1 = containerUp.getWidth();
@@ -119,11 +106,6 @@ public class BlockDivision extends Block {
 		return containerDown;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerUp.computeCaretMaxBound() + containerDown.computeCaretMaxBound();
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) throws Error {
 		final Function upper = getUpperContainer().toFunction(context);
@@ -140,14 +122,11 @@ public class BlockDivision extends Block {
 
 	@Override
 	public ObjectArrayList<BlockContainer> getInnerContainers() {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
+		return innerContainers;
-		output.add(containerUp);
-		output.add(containerDown);
-		return output;
 	}
 
 	@Override
-	public BlockDivision clone(final TreeContainer parent, InputContext ic) {
+	public BlockDivision clone(final BlockContainer parent, InputContext ic) {
 		return new BlockDivision(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockExponentialNotation.java

@@ -18,7 +18,7 @@ public class BlockExponentialNotation extends BlockPower {
 	 * @param old
 	 * @param ic
 	 */
-	private BlockExponentialNotation(final TreeContainer parent, BlockExponentialNotation old, InputContext ic) {
+	private BlockExponentialNotation(final BlockContainer parent, BlockExponentialNotation old, InputContext ic) {
 		super(parent, old, ic);
 		this.bw = old.bw;
 		this.bh = old.bh;
@@ -41,7 +41,7 @@ public class BlockExponentialNotation extends BlockPower {
 	}
 	
 	@Override
-	public BlockExponentialNotation clone(final TreeContainer parent, InputContext ic) {
+	public BlockExponentialNotation clone(final BlockContainer parent, InputContext ic) {
 		return new BlockExponentialNotation(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockLogarithm.java

@@ -27,11 +27,16 @@ public class BlockLogarithm extends Block implements IParenthesis {
 	private int schh;
 	private int nmbh;
 	private int toph;
+	private ObjectArrayList<BlockContainer> innerContainers;
 
 	public BlockLogarithm() {
 		containerBase = new BlockContainer(this, true);
 		containerNumber = new BlockContainer(this, false);
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(2);
+		innerContainers.add(containerBase);
+		innerContainers.add(containerNumber);
 	}
 
 	public BlockLogarithm(final ObjectArrayList<Block> blocks) {
@@ -40,7 +45,7 @@ public class BlockLogarithm extends Block implements IParenthesis {
 		recomputeDimensions();
 	}
 
-	private BlockLogarithm(final TreeContainer parent, BlockLogarithm old, InputContext ic) {
+	private BlockLogarithm(final BlockContainer parent, BlockLogarithm old, InputContext ic) {
 		super(parent, old);
 		containerBase = old.containerBase.clone(this, ic);
 		containerNumber = old.containerNumber.clone(this, ic);
@@ -80,38 +85,16 @@ public class BlockLogarithm extends Block implements IParenthesis {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerBase.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerBase.appendBlock(caret, newBlock);
-		added = added | containerNumber.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerNumber.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-		removed = removed | containerBase.deleteBlock(caret);
-		removed = removed | containerNumber.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		BlockReference<?> bl = null;
-		bl = containerBase.getBlock(caret);
-		if (bl != null) {
-			return bl;
-		}
-		bl = containerNumber.getBlock(caret);
-		return bl;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		if (prefix == null) {
@@ -163,11 +146,6 @@ public class BlockLogarithm extends Block implements IParenthesis {
 		return containerNumber;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerBase.computeCaretMaxBound() + containerNumber.computeCaretMaxBound();
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) throws Error {
 		final Function base = getBaseContainer().toFunction(context);
@@ -185,14 +163,11 @@ public class BlockLogarithm extends Block implements IParenthesis {
 
 	@Override
 	public ObjectArrayList<BlockContainer> getInnerContainers() {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
+		return innerContainers;
-		output.add(containerBase);
-		output.add(containerNumber);
-		return output;
 	}
 
 	@Override
-	public BlockLogarithm clone(final TreeContainer parent, InputContext ic) {
+	public BlockLogarithm clone(final BlockContainer parent, InputContext ic) {
 		return new BlockLogarithm(parent, this, ic);
 	}
 

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockNumericChar.java

@@ -8,12 +8,12 @@ public class BlockNumericChar extends BlockChar {
 		super(ch);
 	}
 
-	private BlockNumericChar(final TreeContainer parent, BlockNumericChar old, InputContext ic) {
+	private BlockNumericChar(final BlockContainer parent, BlockNumericChar old, InputContext ic) {
 		super(parent, old, ic);
 	}
 
 	@Override
-	public BlockNumericChar clone(final TreeContainer parent, InputContext ic) {
+	public BlockNumericChar clone(final BlockContainer parent, InputContext ic) {
 		return new BlockNumericChar(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockOrContainer.java

@@ -0,0 +1,26 @@
+package it.cavallium.warppi.gui.expression.blocks;
+
+import it.cavallium.warppi.gui.GraphicalElement;
+
+public interface BlockOrContainer extends GraphicalElement {
+	BlockOrContainer getParent();
+	BlockOrContainer getAt(int index);
+
+	default void recomputeDimensionsToRoot() {
+		var parent = this;
+		while (parent != null) {
+			parent.recomputeDimensions();
+			parent = parent.getParent();
+		}
+	}
+
+	default BlockContainer getRootContainer() {
+		var parent = this;
+		while (parent != null) {
+			parent = parent.getParent();
+		}
+		return (BlockContainer) parent;
+	}
+
+	int getIndex();
+}

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockParenthesis.java

@@ -9,13 +9,15 @@ import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
 public class BlockParenthesis extends BlockParenthesisAbstract {
+	private ObjectArrayList<BlockContainer> innerContainersCached;
+
 	public BlockParenthesis() {}
 
 	public BlockParenthesis(final ObjectArrayList<Block> blocks) {
 		super(blocks);
 	}
 
-	private BlockParenthesis(final TreeContainer parent, BlockParenthesis old, InputContext ic) {
+	private BlockParenthesis(final BlockContainer parent, BlockParenthesis old, InputContext ic) {
 		super(parent, old, ic);
 	}
 
@@ -31,14 +33,7 @@ public class BlockParenthesis extends BlockParenthesisAbstract {
 	}
 
 	@Override
-	public ObjectArrayList<BlockContainer> getInnerContainers() {
+	public BlockParenthesis clone(final BlockContainer parent, InputContext ic) {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
-		output.add(getNumberContainer());
-		return output;
-	}
-
-	@Override
-	public BlockParenthesis clone(final TreeContainer parent, InputContext ic) {
 		return new BlockParenthesis(parent, this, ic);
 	}
 

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockParenthesisAbstract.java

@@ -14,6 +14,7 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 	private final BlockContainer containerNumber;
 
 	private final String prefix;
+	private final ObjectArrayList<BlockContainer> innerContainers;
 	private int prw;
 	private int chw;
 	private int chh;
@@ -23,12 +24,18 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 		this.prefix = prefix;
 
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
 	public BlockParenthesisAbstract() {
 		containerNumber = new BlockContainer(this, false);
 		prefix = null;
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
 	/**
@@ -36,19 +43,25 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 	 * @param old
 	 * @param ic
 	 */
-	BlockParenthesisAbstract(final TreeContainer parent, BlockParenthesisAbstract old, InputContext ic) {
+	BlockParenthesisAbstract(final BlockContainer parent, BlockParenthesisAbstract old, InputContext ic) {
 		super(parent, old);
 		containerNumber = old.containerNumber.clone(this, ic);
 		prefix = old.prefix;
 		prw = old.prw;
 		chw = old.chw;
 		chh = old.chh;
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
 	public BlockParenthesisAbstract(final ObjectArrayList<Block> blocks) {
 		containerNumber = new BlockContainer(this, false, blocks);
 		prefix = null;
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
 	@Override
@@ -73,30 +86,15 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerNumber.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerNumber.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-		removed = removed | containerNumber.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return containerNumber.getBlock(caret);
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		if (prefix == null) {
@@ -122,11 +120,6 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 		return containerNumber;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerNumber.computeCaretMaxBound();
-	}
-
 	@Override
 	public abstract Feature toFeature(MathContext context) throws Error;
 
@@ -139,9 +132,7 @@ public abstract class BlockParenthesisAbstract extends Block implements IParenth
 
 	@Override
 	public ObjectArrayList<BlockContainer> getInnerContainers() {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
+		return innerContainers;
-		output.add(containerNumber);
-		return output;
 	}
 	
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockPosition.java

@@ -0,0 +1,196 @@
+package it.cavallium.warppi.gui.expression.blocks;
+
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+import it.unimi.dsi.fastutil.ints.IntCollections;
+import org.apache.commons.lang3.NotImplementedException;
+
+import java.util.Collections;
+import java.util.Objects;
+
+public final class BlockPosition {
+    private final BlockOrContainer pos;
+
+	public BlockPosition(BlockOrContainer pos) {
+		this.pos = pos;
+	}
+
+	public BlockPosition(Block block) {
+		this.pos = block;
+	}
+
+	public BlockPosition(BlockContainer container) {
+		this.pos = container;
+	}
+
+	public boolean isBlock() {
+		return pos instanceof Block;
+	}
+
+	public boolean isContainer() {
+		return pos instanceof BlockContainer;
+	}
+
+	public Block getBlock() {
+		return (Block) pos;
+	}
+
+	public BlockContainer getContainer() {
+		return (BlockContainer) pos;
+	}
+
+    public BlockOrContainer get() {
+        return pos;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) return true;
+        if (obj == null || obj.getClass() != this.getClass()) return false;
+        var that = (BlockPosition) obj;
+        return Objects.equals(this.pos, that.pos);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(pos);
+    }
+
+    @Override
+    public String toString() {
+        return "BlockPosition[" +
+                "pos=" + pos + ']';
+    }
+
+	public BlockPosition getNext() {
+		if (pos instanceof BlockContainer) {
+			var container = (BlockContainer) pos;
+			var content = container.getContent();
+			if (content.isEmpty()) {
+				BlockContainer nextContainer;
+				if (container.hasParent()) {
+					var containers = container.getParentBlock().getInnerContainers();
+					var it = containers.listIterator(containers.indexOf(container) + 1);
+					nextContainer = it.hasNext() ? it.next() : null;
+				} else {
+					nextContainer = null;
+				}
+				if (nextContainer != null) {
+					return new BlockPosition(nextContainer);
+				} else {
+					var parentBlock = container.getParentBlock();
+					return parentBlock != null ? new BlockPosition(parentBlock) : null;
+				}
+			} else {
+				var targetBlock = content.get(0);
+				var innerContainers = targetBlock.getInnerContainers();
+				if (innerContainers != null && !innerContainers.isEmpty()) {
+					return new BlockPosition(innerContainers.get(0));
+				} else {
+					return new BlockPosition(targetBlock);
+				}
+			}
+		} else if (pos instanceof Block) {
+			var block = (Block) pos;
+			var ref = block.getReference();
+			var nextBlock = ref.getNextBlock();
+			if (nextBlock == null) {
+				var container = block.getParentContainer();
+				BlockContainer nextContainer;
+				if (container.hasParent()) {
+					var containers = container.getParentBlock().getInnerContainers();
+					var it = containers.listIterator(containers.indexOf(container) + 1);
+					nextContainer = it.hasNext() ? it.next() : null;
+				} else {
+					nextContainer = null;
+				}
+				if (nextContainer != null) {
+					return new BlockPosition(nextContainer);
+				} else {
+					var parentBlock = container.getParentBlock();
+					return parentBlock != null ? new BlockPosition(parentBlock) : null;
+				}
+			} else {
+				var targetBlock = nextBlock.get();
+				var innerContainers = targetBlock.getInnerContainers();
+				if (innerContainers != null && !innerContainers.isEmpty()) {
+					return new BlockPosition(innerContainers.get(0));
+				} else {
+					return new BlockPosition(targetBlock);
+				}
+			}
+		} else {
+			throw new UnsupportedOperationException();
+		}
+	}
+
+	public BlockPosition getPrevious() {
+		if (pos instanceof BlockContainer) {
+			var container = (BlockContainer) pos;
+			if (container.hasParent()) {
+				var parentBlock = container.getParentBlock();
+				var innerContainers = parentBlock.getInnerContainers();
+				if (innerContainers != null) {
+					var it = innerContainers.listIterator(innerContainers.indexOf(container));
+					if (it.hasPrevious()) {
+						var prevContainer = it.previous();
+						var prevContainerLastBlock = prevContainer.getLastBlock();
+						if (prevContainerLastBlock != null) {
+							return new BlockPosition(prevContainerLastBlock);
+						} else {
+							return new BlockPosition(prevContainer);
+						}
+					} else {
+						var parentContainer = parentBlock.getParentContainer();
+						var blocks = parentContainer.getContentUnsafe();
+						var bIt = blocks.listIterator(blocks.indexOf(parentBlock));
+						if (bIt.hasPrevious()) {
+							return new BlockPosition(bIt.previous());
+						} else {
+							return new BlockPosition(parentContainer);
+						}
+					}
+				} else {
+					throw new UnsupportedOperationException();
+				}
+			} else {
+				return null;
+			}
+		} else if (pos instanceof Block) {
+			var block = (Block) pos;
+			var innerContainers = block.getInnerContainers();
+			if (innerContainers != null) {
+				var lastContainer = innerContainers.get(innerContainers.size() - 1);
+				var lastBlock = lastContainer.getLastBlock();
+				if (lastBlock != null) {
+					return new BlockPosition(lastBlock);
+				} else {
+					return new BlockPosition(lastContainer);
+				}
+			}
+			var ref = block.getReference();
+			var prevBlock = ref.getPreviousBlock();
+			if (prevBlock == null) {
+				var container = block.getParentContainer();
+				return new BlockPosition(container);
+			} else {
+				var targetBlock = prevBlock.get();
+				return new BlockPosition(targetBlock);
+			}
+		} else {
+			throw new UnsupportedOperationException();
+		}
+	}
+
+	public IntArrayList getURL() {
+		var url = new IntArrayList();
+		var parent = pos;
+		while (parent != null) {
+			var index = parent.getIndex();
+			if (index == -1) break;
+			url.add(index);
+			parent = parent.getParent();
+		}
+		Collections.reverse(url);
+		return url;
+	}
+}

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockPower.java

@@ -14,15 +14,22 @@ import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 public class BlockPower extends Block {
 
 	private final BlockContainer containerExponent;
+	private final ObjectArrayList<BlockContainer> innerContainers;
 
 	public BlockPower() {
 		containerExponent = new BlockContainer(this, true);
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerExponent);
 	}
 
-	protected BlockPower(final TreeContainer parent, BlockPower old, InputContext ic) {
+	protected BlockPower(final BlockContainer parent, BlockPower old, InputContext ic) {
 		super(parent, old);
 		this.containerExponent = old.containerExponent.clone(this, ic);
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerExponent);
 	}
 
 	@Override
@@ -33,29 +40,14 @@ public class BlockPower extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerExponent.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerExponent.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
-	
-	@Override
-	public boolean deleteBlock(Caret caret) {
-		boolean removed = false;
-		removed = removed | containerExponent.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return containerExponent.getBlock(caret);
-	}
 
 	@Override
 	public void recomputeDimensions() {
@@ -77,11 +69,6 @@ public class BlockPower extends Block {
 		return containerExponent;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerExponent.computeCaretMaxBound();
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) throws Error {
 		final Function exp = getExponentContainer().toFunction(context);
@@ -95,13 +82,11 @@ public class BlockPower extends Block {
 
 	@Override
 	public ObjectArrayList<BlockContainer> getInnerContainers() {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
+		return innerContainers;
-		output.add(containerExponent);
-		return output;
 	}
 
 	@Override
-	public BlockPower clone(final TreeContainer parent, InputContext ic) {
+	public BlockPower clone(final BlockContainer parent, InputContext ic) {
 		return new BlockPower(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockPower2.java

@@ -14,21 +14,23 @@ import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 public class BlockPower2 extends Block {
 
 	private final BlockContainer containerExponent;
+	private final ObjectArrayList<BlockContainer> innerContainers;
 
 	public BlockPower2() {
 		containerExponent = new BlockContainer(this, true);
 		containerExponent.addBlock(0, new BlockNumericChar('2'));
 		recomputeDimensions();
+
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerExponent);
 	}
 
-	private BlockPower2(final TreeContainer parent, BlockPower2 old, InputContext ic) {
+	private BlockPower2(final BlockContainer parent, BlockPower2 old, InputContext ic) {
 		super(parent, old);
 		this.containerExponent = old.containerExponent.clone(this, ic);
-	}
 
-	@Override
+		innerContainers = new ObjectArrayList<>(1);
-	public int getCaretDeltaPositionAfterCreation() {
+		innerContainers.add(containerExponent);
-		return 3;
 	}
 
 	@Override
@@ -39,30 +41,15 @@ public class BlockPower2 extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerExponent.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerExponent.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-		removed = removed | containerExponent.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return containerExponent.getBlock(caret);
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		final int w2 = containerExponent.getWidth();
@@ -83,11 +70,6 @@ public class BlockPower2 extends Block {
 		return containerExponent;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerExponent.computeCaretMaxBound();
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) throws Error {
 		final Function exp = getExponentContainer().toFunction(context);
@@ -101,13 +83,11 @@ public class BlockPower2 extends Block {
 
 	@Override
 	public ObjectArrayList<BlockContainer> getInnerContainers() {
-		ObjectArrayList<BlockContainer> output = new ObjectArrayList<>();
+		return innerContainers;
-		output.add(containerExponent);
-		return output;
 	}
 
 	@Override
-	public BlockPower2 clone(final TreeContainer parent, InputContext ic) {
+	public BlockPower2 clone(final BlockContainer parent, InputContext ic) {
 		return new BlockPower2(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockReference.java

@@ -1,13 +1,17 @@
 package it.cavallium.warppi.gui.expression.blocks;
 
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+
 public class BlockReference<T extends Block> {
 	private final T block;
 	private final BlockContainer container;
-	private final int blockPosition;
+	private int cachedBlockPosition;
+	private final ObjectArrayList<Block> containerBlocks;
 
-	public BlockReference(final T block, final int blockPosition, final BlockContainer container) {
+	public BlockReference(final T block, final int cachedBlockPosition, final ObjectArrayList<Block> containerBlocks, final BlockContainer container) {
 		this.block = block;
-		this.blockPosition = blockPosition;
+		this.cachedBlockPosition = cachedBlockPosition;
+		this.containerBlocks = containerBlocks;
 		this.container = container;
 	}
 
@@ -20,23 +24,28 @@ public class BlockReference<T extends Block> {
 	}
 
 	public int getIndex() {
-		return blockPosition;
+		if (containerBlocks.size() > cachedBlockPosition && cachedBlockPosition >= 0
+			&& containerBlocks.get(cachedBlockPosition) == block) {
+			return cachedBlockPosition;
+		} else {
+			return cachedBlockPosition = containerBlocks.indexOf(block);
+		}
 	}
 
 	public BlockReference<?> getNextBlock() {
-		return getBlockAtSafe(this.blockPosition + 1);
+		return getBlockAtSafe(getIndex() + 1);
 	}
 
 	public boolean hasNextBlock() {
-		return isInsideBounds(this.blockPosition + 1);
+		return isInsideBounds(getIndex() + 1);
 	}
 
 	public BlockReference<?> getPreviousBlock() {
-		return getBlockAtSafe(this.blockPosition - 1);
+		return getBlockAtSafe(getIndex() - 1);
 	}
 
 	public boolean hasPreviousBlock() {
-		return isInsideBounds(this.blockPosition - 1);
+		return isInsideBounds(getIndex() - 1);
 	}
 
 	private BlockReference<?> getBlockAtSafe(final int i) {

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockSine.java

@@ -13,7 +13,7 @@ public class BlockSine extends BlockParenthesisAbstract {
 		super("SIN");
 	}
 
-	private BlockSine(final TreeContainer parent, BlockSine old, InputContext ic) {
+	private BlockSine(final BlockContainer parent, BlockSine old, InputContext ic) {
 		super(parent, old, ic);
 	}
 
@@ -24,7 +24,7 @@ public class BlockSine extends BlockParenthesisAbstract {
 	}
 
 	@Override
-	public BlockSine clone(final TreeContainer parent, InputContext ic) {
+	public BlockSine clone(final BlockContainer parent, InputContext ic) {
 		return new BlockSine(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockSquareRoot.java

@@ -14,18 +14,23 @@ import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 public class BlockSquareRoot extends Block {
 
 	private final BlockContainer containerNumber;
+	private final ObjectArrayList<BlockContainer> innerContainers;
 
 	private int h1;
 
 	public BlockSquareRoot() {
 		containerNumber = new BlockContainer(this, false);
 		recomputeDimensions();
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
-	private BlockSquareRoot(final TreeContainer parent, BlockSquareRoot old, InputContext ic) {
+	private BlockSquareRoot(final BlockContainer parent, BlockSquareRoot old, InputContext ic) {
 		super(parent, old);
 		this.containerNumber = old.containerNumber.clone(this, ic);
 		this.h1 = old.h1;
+		innerContainers = new ObjectArrayList<>(1);
+		innerContainers.add(containerNumber);
 	}
 
 	@Override
@@ -44,30 +49,15 @@ public class BlockSquareRoot extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		boolean added = false;
-		added = added | containerNumber.appendBlock(caret, newBlock, splitAdjacent);
+		added = added | containerNumber.appendBlock(caret, newBlock);
 		if (added) {
 			recomputeDimensions();
 		}
 		return added;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		boolean removed = false;
-		removed = removed | containerNumber.deleteBlock(caret);
-		if (removed) {
-			recomputeDimensions();
-		}
-		return removed;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return containerNumber.getBlock(caret);
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		final int w1 = containerNumber.getWidth();
@@ -93,11 +83,6 @@ public class BlockSquareRoot extends Block {
 		return containerNumber;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return containerNumber.computeCaretMaxBound();
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) throws Error {
 		final Function contnt = getNumberContainer().toFunction(context);
@@ -119,7 +104,7 @@ public class BlockSquareRoot extends Block {
 	}
 
 	@Override
-	public BlockSquareRoot clone(final TreeContainer parent, InputContext ic) {
+	public BlockSquareRoot clone(final BlockContainer parent, InputContext ic) {
 		return new BlockSquareRoot(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockUndefined.java

@@ -16,7 +16,7 @@ public class BlockUndefined extends Block {
 		recomputeDimensions();
 	}
 
-	private BlockUndefined(final TreeContainer parent, BlockUndefined old, InputContext ic) {
+	private BlockUndefined(final BlockContainer parent, BlockUndefined old, InputContext ic) {
 		super(parent, old);
 	}
 
@@ -28,20 +28,10 @@ public class BlockUndefined extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		return false;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		return false;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return null;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		width = BlockContainer.getDefaultFont(small).getStringWidth("UNDEFINED");
@@ -55,11 +45,6 @@ public class BlockUndefined extends Block {
 		recomputeDimensions();
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return 0;
-	}
-
 	@Override
 	public Feature toFeature(final MathContext context) {
 		return new FeatureChar(MathematicalSymbols.UNDEFINED);
@@ -76,7 +61,7 @@ public class BlockUndefined extends Block {
 	}
 
 	@Override
-	public BlockUndefined clone(final TreeContainer parent, InputContext ic) {
+	public BlockUndefined clone(final BlockContainer parent, InputContext ic) {
 		return new BlockUndefined(parent, this, ic);
 	}
 

core/src/main/java/it/cavallium/warppi/gui/expression/blocks/BlockVariable.java

@@ -43,7 +43,7 @@ public class BlockVariable extends Block {
 		recomputeDimensions();
 	}
 
-	private BlockVariable(final TreeContainer parent, BlockVariable old, InputContext ic) {
+	private BlockVariable(final BlockContainer parent, BlockVariable old, InputContext ic) {
 		super(parent, old);
 		this.ic = ic;
 		this.ch = old.ch;
@@ -106,20 +106,10 @@ public class BlockVariable extends Block {
 	}
 
 	@Override
-	public boolean appendBlock(final Caret caret, final Block newBlock, boolean splitAdjacent) {
+	public boolean appendBlock(final Caret caret, final Block newBlock) {
 		return false;
 	}
 
-	@Override
-	public boolean deleteBlock(final Caret caret) {
-		return false;
-	}
-
-	@Override
-	public BlockReference<?> getBlock(final Caret caret) {
-		return null;
-	}
-
 	@Override
 	public void recomputeDimensions() {
 		width = BlockContainer.getDefaultCharWidth(small);
@@ -137,11 +127,6 @@ public class BlockVariable extends Block {
 		return ch;
 	}
 
-	@Override
-	public int computeCaretMaxBound() {
-		return 0;
-	}
-
 	@Override
 	public ExtraMenu<?> getExtraMenu() {
 		return menu;
@@ -271,7 +256,7 @@ public class BlockVariable extends Block {
 		}
 
 		@Override
-		public VariableMenu clone(final TreeContainer parent, InputContext ic) {
+		public VariableMenu clone(final BlockContainer parent, InputContext ic) {
 			return new VariableMenu(this, block.clone(parent, ic));
 		}
 
@@ -293,7 +278,7 @@ public class BlockVariable extends Block {
 	}
 	
 	@Override
-	public BlockVariable clone(final TreeContainer parent, InputContext ic) {
+	public BlockVariable clone(final BlockContainer parent, InputContext ic) {
 		return new BlockVariable(parent, this, ic);
 	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/containers/InputContainer.java

@@ -7,10 +7,7 @@ import it.cavallium.warppi.gui.expression.Caret;
 import it.cavallium.warppi.gui.expression.CaretState;
 import it.cavallium.warppi.gui.expression.ExtraMenu;
 import it.cavallium.warppi.gui.expression.InputContext;
-import it.cavallium.warppi.gui.expression.blocks.Block;
+import it.cavallium.warppi.gui.expression.blocks.*;
-import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
-import it.cavallium.warppi.gui.expression.blocks.BlockDivision;
-import it.cavallium.warppi.gui.expression.blocks.BlockReference;
 import it.cavallium.warppi.gui.expression.layouts.InputLayout;
 import it.cavallium.warppi.gui.graphicengine.Renderer;
 import it.cavallium.warppi.math.Function;
@@ -23,7 +20,6 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	protected Caret caret;
 	private static final float CARET_DURATION = 0.5f;
 	private float caretTime;
-	private int maxPosition = 0;
 	private boolean parsed = false;
 	private ExtraMenu<?> extra;
 	protected InputContext inputContext;
@@ -50,8 +46,8 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 
 	public InputContainer(final InputContext ic, final boolean small, final int minWidth, final int minHeight) {
 		inputContext = ic;
-		caret = new Caret(CaretState.VISIBLE_ON, 0);
 		root = new BlockContainer(null, small, false);
+		caret = new Caret(CaretState.VISIBLE_ON, new BlockPosition(root));
 	}
 	
 	/**
@@ -62,10 +58,9 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	protected InputContainer(InputContainer old, InputContext ic) {
 		this.caretTime = old.caretTime;
 		this.extra = old.extra == null ? null : old.extra.clone(null, ic);
-		this.maxPosition = old.maxPosition;
-		this.caret = old.caret == null ? null : new Caret(old.caret);
 		this.inputContext = ic;
 		this.root = old.root == null ? null : old.root.clone(null, ic);
+		this.caret = old.caret == null ? null : new Caret(old.caret, root);
 		this.parsed = old.parsed;
 	}
 
@@ -76,14 +71,9 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 
 	public void typeBlock(final Block b) {
 		if (b != null) {
-			caret.resetRemaining();
+			if (root.appendBlock(caret, b)) {
-
+				var innerPos = b.getFirstInnerPosition();
-			// todo: allow blocks to dinamically choose insert mode
+				caret.setPosition(innerPos == null ? new BlockPosition(b) : innerPos);
-			var splitAdjacent = b instanceof BlockDivision;
-
-			if (root.appendBlock(caret, b, splitAdjacent)) {
-				caret.setPosition(caret.getPosition() + b.getCaretDeltaPositionAfterCreation());
-				maxPosition = root.computeCaretMaxBound();
 				root.recomputeDimensions();
 			}
 			closeExtra();
@@ -97,13 +87,71 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	}
 
 	public void del() {
-		caret.resetRemaining();
+		var pos = caret.getPos();
-		if (root.deleteBlock(caret)) {
+		BlockOrContainer currentElementToRecompute;
-			root.recomputeDimensions();
+		boolean removed;
+		if (pos.isBlock()) {
+			var block = pos.getBlock();
+			var lastInnerPosition = block.getLastInnerPosition();
+			if (lastInnerPosition != null) {
+				caret.setPosition(lastInnerPosition);
+				currentElementToRecompute = null;
+				removed = false;
+			} else {
+				caret.setPosition(pos.getPrevious());
+				var parent = block.getParentContainer();
+				parent.removeBlockUnsafe(block);
+				currentElementToRecompute = parent;
+				removed = true;
+			}
+		} else if (pos.isContainer()) {
+			var container = pos.getContainer();
+			if (container == root) {
+				currentElementToRecompute = null;
+				removed = false;
+			} else if (!container.hasParent()) {
+				throw new IllegalStateException();
+			} else {
+				var block = container.getParentBlock();
+				var containers = block.getInnerContainers();
+				BlockContainer prevContainer;
+				if (containers == null) {
+					prevContainer = null;
+				} else {
+					var containerIt = containers.listIterator(containers.indexOf(container));
+					if (containerIt.hasPrevious()) {
+						prevContainer = containerIt.previous();
+					} else {
+						prevContainer = null;
+					}
+				}
+				if (prevContainer != null) {
+					var lastBlock = prevContainer.getLastBlock();
+					if (lastBlock != null) {
+						caret.setPosition(new BlockPosition(lastBlock));
+						currentElementToRecompute = null;
+						removed = false;
+					} else {
+						caret.setPosition(new BlockPosition(prevContainer));
+						currentElementToRecompute = null;
+						removed = false;
+					}
+				} else {
+					caret.setPosition(pos.getPrevious());
+					var parentContainer = block.getParentContainer();
+					parentContainer.removeBlockUnsafe(block);
+					currentElementToRecompute = parentContainer;
+					removed = true;
+				}
+			}
+		} else {
+			throw new UnsupportedOperationException();
 		}
-		if (caret.getPosition() > 0) {
+		if (removed) {
-			caret.setPosition(caret.getPosition() - 1);
+			while (currentElementToRecompute != null) {
-			maxPosition = root.computeCaretMaxBound();
+				currentElementToRecompute.recomputeDimensions();
+				currentElementToRecompute = currentElementToRecompute.getParent();
+			}
 		}
 		caret.turnOn();
 		caretTime = 0;
@@ -111,46 +159,25 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	}
 
 	public BlockReference<?> getSelectedBlock() {
-		caret.resetRemaining();
+		var pos = caret.getPos();
-		final BlockReference<?> selectedBlock = root.getBlock(caret);
+		if (pos.isBlock()) {
-		return selectedBlock;
+			return pos.getBlock().getReference();
-	}
+		} else {
-
+			var container = pos.getContainer();
-	public BlockReference<?> getBlockAtCaretPosition(final int i) {
+			if (container.hasParent()) {
-		final BlockReference<?> selectedBlock = root.getBlock(new Caret(CaretState.HIDDEN, i));
+				return container.getParentBlock().getReference();
-		return selectedBlock;
+			} else {
+				return null;
+			}
+		}
 	}
 
 	public void moveLeft() {
-		final int curPos = caret.getPosition();
+		var prev = caret.getPos().getPrevious();
-		if (curPos > 0) {
+		if (prev != null) {
-			caret.setPosition(curPos - 1);
+			caret.setPosition(prev);
 		} else {
-			caret.setPosition(maxPosition - 1);
+			caret.setPosition(new BlockPosition(root.getLastBlock()));
-		}
-		caret.turnOn();
-		caretTime = 0;
-		closeExtra();
-	}
-
-	public void moveRight(final int delta) {
-		
-		final int curPos = caret.getPosition();
-		if (curPos + delta < maxPosition) {
-			caret.setPosition(curPos + delta);
-		} else {
-			caret.setPosition(0);
-		}
-		caret.turnOn();
-		caretTime = 0;
-		closeExtra();
-	}
-
-	public void moveTo(final int position) {
-		if (position < maxPosition) {
-			caret.setPosition(position);
-		} else {
-			caret.setPosition(0);
 		}
 		caret.turnOn();
 		caretTime = 0;
@@ -158,7 +185,22 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	}
 
 	public void moveRight() {
-		moveRight(1);
+		var prev = caret.getPos().getNext();
+		if (prev != null) {
+			caret.setPosition(prev);
+		} else {
+			caret.setPosition(new BlockPosition(root));
+		}
+		caret.turnOn();
+		caretTime = 0;
+		closeExtra();
+	}
+
+	public void moveTo(final BlockPosition position) {
+		caret.setPosition(position);
+		caret.turnOn();
+		caretTime = 0;
+		closeExtra();
 	}
 
 	@Override
@@ -217,7 +259,6 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	 *            Position relative to the window.
 	 */
 	public void draw(final DisplayOutputDevice ge, final Renderer r, final int x, final int y) {
-		caret.resetRemaining();
 		root.draw(ge, r, x, y, caret);
 		if (extra != null) {
 			extra.draw(ge, r, caret);
@@ -225,27 +266,13 @@ public abstract class InputContainer implements GraphicalElement, InputLayout {
 	}
 
 	public void clear() {
-		caret = new Caret(CaretState.VISIBLE_ON, 0);
+		caret = new Caret(CaretState.VISIBLE_ON, new BlockPosition(root));
 		root.clear();
-		maxPosition = root.computeCaretMaxBound();
 		recomputeDimensions();
 	}
 
 	public boolean isEmpty() {
-		return maxPosition <= 1;
+		return root.getSize() == 0;
-	}
-
-	public int getCaretMaxPosition() {
-		return maxPosition;
-	}
-
-	public void setCaretPosition(final int pos) {
-		if (pos > 0 && pos < maxPosition) {
-			caret.setPosition(pos);
-		}
-		caret.turnOn();
-		caretTime = 0;
-		closeExtra();
 	}
 
 	public void setParsed(final boolean parsed) {

core/src/main/java/it/cavallium/warppi/gui/expression/containers/NormalInputContainer.java

@@ -6,6 +6,9 @@ import it.cavallium.warppi.gui.expression.InputContext;
 import it.cavallium.warppi.gui.expression.blocks.*;
 import it.cavallium.warppi.math.MathematicalSymbols;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class NormalInputContainer extends InputContainer {
 
 	@Deprecated()
@@ -30,7 +33,6 @@ public class NormalInputContainer extends InputContainer {
 
 	/**
 	 * Copy
-	 * @param userInput
 	 * @param ic
 	 */
 	public NormalInputContainer(InputContainer old, InputContext ic) {
@@ -93,36 +95,24 @@ public class NormalInputContainer extends InputContainer {
 		switch (c) {
 			case MathematicalSymbols.PARENTHESIS_CLOSE: {
 				final BlockReference<?> ref = getSelectedBlock();
-				if (ref == null) {
+				BlockParenthesisAbstract parenthesis = findParenthesis(ref.get());
+				if (parenthesis == null) {
 					break;
 				} else {
-					final Caret newCaret = new Caret(CaretState.HIDDEN, caret.getPosition());
+					moveTo(new BlockPosition(parenthesis));
-					BlockContainer currentContainer;
-					BlockReference<?> newRef = ref;
-					int safeExit = 0;
-					do {
-						currentContainer = (BlockContainer) newRef.get().getParentContainer();
-						final int initialRelativeIndex = currentContainer.getContent().indexOf(newRef.get());
-						final int newIndex = newCaret.getPosition() + currentContainer.getContent().size() - initialRelativeIndex;
-						newRef = getBlockAtCaretPosition(newIndex);
-						newCaret.setPosition(newIndex);
-						safeExit++;
-					} while (newRef != null && newRef.get() instanceof IParenthesis == false && currentContainer != null && safeExit < 100000);
-					if (safeExit >= 100000) {
-						System.err.println("Error 0x001030: Infinite loop");
-					}
-					if (newRef != null) {
-						moveTo(newCaret.getPosition());
-					}
 				}
 				break;
 			}
+			case MathematicalSymbols.POWER_OF_TWO:
+				moveTo(new BlockPosition(getSelectedBlock().get()));
+				break;
 			case MathematicalSymbols.DIVISION: {
 				@SuppressWarnings("unchecked")
 				final BlockReference<BlockDivision> ref = (BlockReference<BlockDivision>) getSelectedBlock();
 				@SuppressWarnings("unused")
 				final BlockContainer parentContainer = ref.getContainer();
 				BlockReference<?> currentBlock = ref;
+				List<Block> blocksToMove = new ArrayList<>();
 				boolean groupedBefore = false;
 				int before = 0;
 				while (true) {
@@ -135,28 +125,39 @@ public class NormalInputContainer extends InputContainer {
 						if (!groupedBefore) {
 							groupedBefore = true;
 						}
+						blocksToMove.add(b);
 						before++;
 					} else {
 						break;
 					}
 				}
 				if (groupedBefore) {
-					moveLeft();
+					var div = ref.get();
-					for (int i = 0; i < before; i++) {
+					var upperContainer = div.getUpperContainer();
-						final BlockReference<?> b = getSelectedBlock();
+					for (int i = blocksToMove.size() - 1; i >= 0; i--) {
-						del();
+						var b = blocksToMove.get(i);
-						moveRight();
+						b.getParentContainer().removeBlockUnsafe(b);
-						typeBlock(b.get());
+						upperContainer.appendBlock(b);
-						moveLeft();
-						moveLeft();
 					}
-					for (int i = 0; i < before + 1; i++) {
+					div.recomputeDimensionsToRoot();
-						moveRight();
+					moveTo(new BlockPosition(div.getLowerContainer()));
-					}
-					moveRight();// Move to the divisor
 				}
 				break;
 			}
 		}
 	}
+
+	private BlockParenthesisAbstract findParenthesis(Block o) {
+		while (!(o instanceof BlockParenthesisAbstract)) {
+			var pc = o.getParentContainer();
+			if (!pc.hasParent()) {
+				return null;
+			}
+			o = pc.getParentBlock();
+			if (o == null) {
+				return null;
+			}
+		}
+		return (BlockParenthesisAbstract) o;
+	}
 }

core/src/main/java/it/cavallium/warppi/gui/expression/containers/OutputContainer.java

@@ -6,6 +6,7 @@ import it.cavallium.warppi.gui.expression.Caret;
 import it.cavallium.warppi.gui.expression.CaretState;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
+import it.cavallium.warppi.gui.expression.blocks.BlockPosition;
 import it.cavallium.warppi.gui.expression.layouts.OutputLayout;
 import it.cavallium.warppi.gui.graphicengine.Renderer;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -13,21 +14,27 @@ import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 public abstract class OutputContainer implements GraphicalElement, OutputLayout {
 	private static final long serialVersionUID = -5714825964892683571L;
 	public final ObjectArrayList<BlockContainer> roots;
-	private final Caret caret = new Caret(CaretState.HIDDEN, 0);
+	private final Caret caret;
 
 	public OutputContainer() {
 		roots = new ObjectArrayList<>();
-		roots.add(new BlockContainer());
+		var root = new BlockContainer();
+		roots.add(root);
+		caret = new Caret(CaretState.HIDDEN, new BlockPosition(root));
 	}
 
 	public OutputContainer(final boolean small) {
 		roots = new ObjectArrayList<>();
-		roots.add(new BlockContainer(null, small));
+		var root = new BlockContainer(null, small);
+		roots.add(root);
+		caret = new Caret(CaretState.HIDDEN, new BlockPosition(root));
 	}
 
 	public OutputContainer(final boolean small, final int minWidth, final int minHeight) {
 		roots = new ObjectArrayList<>();
-		roots.add(new BlockContainer(null, small));
+		var root = new BlockContainer(null, small);
+		roots.add(root);
+		caret = new Caret(CaretState.HIDDEN, new BlockPosition(root));
 	}
 
 	public void setContentAsSingleGroup(final ObjectArrayList<Block> blocks) {