From 2e0b653b48853ea35a2a173ec37cc917fd4a7a77 Mon Sep 17 00:00:00 2001
From: Aaron Seigo <aseigo@kde.org>
Date: Mon, 11 Jul 2011 21:46:34 +0200
Subject: [PATCH] paint in parent coords, do events in local coords

this makes clicking on the window previews accurate (e.g. clicking at the top of them works)
also some code consistency when iterating over the collections and some cleanups
---
 private/windowpreview.cpp | 51 ++++++++++++++++++---------------------
 1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/private/windowpreview.cpp b/private/windowpreview.cpp
index 2e7ddfb61..8df0f2e5d 100644
--- a/private/windowpreview.cpp
+++ b/private/windowpreview.cpp
@@ -133,8 +133,9 @@ bool WindowPreview::highlightWindows() const
 
 void WindowPreview::setInfo()
 {
+    QWidget *w = parentWidget();
     if (isEmpty()) {
-        WindowEffects::showWindowThumbnails(parentWidget()->winId());
+        WindowEffects::showWindowThumbnails(w->winId());
         return;
     }
 
@@ -143,11 +144,11 @@ void WindowPreview::setInfo()
     }
 
     if (windowSizes.size() == 0) {
-        WindowEffects::showWindowThumbnails(parentWidget()->winId());
+        WindowEffects::showWindowThumbnails(w->winId());
         return;
     }
 
-    Q_ASSERT(parentWidget()->isWindow()); // parent must be toplevel
+    Q_ASSERT(w->isWindow()); // parent must be toplevel
 
     QSize thumbnailSize = sizeHint();
     thumbnailSize.scale(size(), Qt::KeepAspectRatio);
@@ -155,21 +156,24 @@ void WindowPreview::setInfo()
 
     qreal left, top, right, bottom;
     m_background->getMargins(left, top, right, bottom);
-    QRect thumbnailRect = geometry().adjusted(left, top, -right, -bottom);
-
+    const QRect thumbnailRect(QPoint(left, top), size() - QSize(left + right, top + bottom));
     const int numWindows = ids.size();
+    const qreal thumbWidth = (thumbnailRect.width() - WINDOW_MARGIN*(numWindows - 1)) / numWindows;
 
+    // we paint in parent coords, but accept events in local coords
+    QList<QRect> inParentCoords;
     m_thumbnailRects.clear();
-    int x = thumbnailRect.x();
 
+    int x = thumbnailRect.x();
     foreach (QSize s, windowSizes) {
-        s.scale((qreal)(thumbnailRect.width()-WINDOW_MARGIN*(numWindows-1))/numWindows, thumbnailRect.height(), Qt::KeepAspectRatio);
+        s.scale(thumbWidth, thumbnailRect.height(), Qt::KeepAspectRatio);
         int y = thumbnailRect.y() + (thumbnailRect.height() - s.height())/2;
-        m_thumbnailRects.append(QRect(QPoint(x,y), s));
+        m_thumbnailRects.append(QRect(QPoint(x, y), s));
+        inParentCoords.append(QRect(mapToParent(QPoint(x, y)), s));
         x += s.width() + WINDOW_MARGIN;
     }
 
-    WindowEffects::showWindowThumbnails(parentWidget()->winId(), ids, m_thumbnailRects);
+    WindowEffects::showWindowThumbnails(w->winId(), ids, inParentCoords);
 }
 
 void WindowPreview::paintEvent(QPaintEvent *e)
@@ -180,30 +184,24 @@ void WindowPreview::paintEvent(QPaintEvent *e)
 
     qreal left, top, right, bottom;
     m_background->getMargins(left, top, right, bottom);
+    const QSize delta(left + right, top + bottom);
+    const QPoint topLeft(left, top);
 
     foreach (const QRect &r, m_thumbnailRects) {
         //kWarning()<<r;
-        m_background->resizeFrame(r.size()+QSize(left+right, top+bottom));
-        m_background->paintFrame(&painter, r.topLeft()-pos()-QPoint(left,top));
+        m_background->resizeFrame(r.size() + delta);
+        m_background->paintFrame(&painter, r.topLeft() - topLeft);
     }
-
 }
 
 void WindowPreview::mousePressEvent(QMouseEvent *event)
 {
-    QPoint p = event->pos();
-    WId wid = 0;
-
     for (int i = 0; i < m_thumbnailRects.size(); ++i) {
-        if (m_thumbnailRects[i].contains(p)) {
-            wid = ids[i];
-            break;
+        if (m_thumbnailRects[i].contains(event->pos())) {
+            emit windowPreviewClicked(ids[i], event->buttons(), event->modifiers(), event->globalPos());
+            return;
         }
     }
-
-    if (wid) {
-        emit windowPreviewClicked(wid, event->buttons(), event->modifiers(), event->globalPos());
-    }
 }
 
 void WindowPreview::mouseMoveEvent(QMouseEvent *event)
@@ -212,14 +210,13 @@ void WindowPreview::mouseMoveEvent(QMouseEvent *event)
         return;
     }
 
-    int i = 0;
-    foreach (const QRect &rect, m_thumbnailRects) {
-        if (rect.contains(event->pos())) {
-            WindowEffects::highlightWindows(effectiveWinId(), QList<WId>()<<effectiveWinId()<<ids[i]);
+    for (int i = 0; i < m_thumbnailRects.size(); ++i) {
+        if (m_thumbnailRects[i].contains(event->pos())) {
+            WindowEffects::highlightWindows(effectiveWinId(), QList<WId>() << effectiveWinId() << ids[i]);
             return;
         }
-        ++i;
     }
+
     WindowEffects::highlightWindows(effectiveWinId(), QList<WId>());
 }