From 0395977fdec07c16280e1dd69cd850bf7c609c85 Mon Sep 17 00:00:00 2001
From: cpfeiffer <cpfeiffer@users.noreply.github.com>
Date: Sun, 27 Sep 2015 00:10:33 +0200
Subject: [PATCH] Some work for properly animating our single (value-changing)
 entry

---
 .../charts/SingleEntryValueAnimator.java      | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/charts/SingleEntryValueAnimator.java

diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/charts/SingleEntryValueAnimator.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/charts/SingleEntryValueAnimator.java
new file mode 100644
index 000000000..b423505bb
--- /dev/null
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/charts/SingleEntryValueAnimator.java
@@ -0,0 +1,48 @@
+package nodomain.freeyourgadget.gadgetbridge.activities.charts;
+
+import android.animation.Animator;
+import android.animation.ObjectAnimator;
+import android.animation.ValueAnimator;
+
+import com.github.mikephil.charting.animation.ChartAnimator;
+import com.github.mikephil.charting.data.Entry;
+
+public class SingleEntryValueAnimator extends ChartAnimator {
+    private final Entry entry;
+    private final ValueAnimator.AnimatorUpdateListener listener;
+    private float previousValue;
+
+    public SingleEntryValueAnimator(Entry singleEntry, ValueAnimator.AnimatorUpdateListener listener) {
+        super(listener);
+        this.listener = listener;
+        entry = singleEntry;
+    }
+
+    public void setEntryYValue(float value) {
+        this.previousValue = entry.getVal();
+        entry.setVal(value);
+    }
+
+    @Override
+    public void animateY(int durationMillis) {
+        // we start with the previous value and animate the change to the
+        // next value.
+        // as our animation values are not used as absolute values, but as factors,
+        // we have to calculate the proper factors in advance. The entry already has
+        // the new value, so we create a factor to calculate the old value from the
+        // new value.
+
+        float startAnim;
+        float endAnim = 1f;
+        if (entry.getVal() == 0f) {
+            startAnim = 0f;
+        } else {
+            startAnim = previousValue / entry.getVal();
+        }
+
+        ObjectAnimator animatorY = ObjectAnimator.ofFloat(this, "phaseY", startAnim, endAnim);
+        animatorY.setDuration(durationMillis);
+        animatorY.addUpdateListener(listener);
+        animatorY.start();
+    }
+}