DisassemblerGraphView zooming fix (#1354)

* Zooming of DisassemblerGraphView now works to cursor instead of top left corner.

* formatting fix.

* Fix refactor bug.

src/core/MainWindow.cpp

@@ -392,10 +392,10 @@ void MainWindow::drawOverview()
     qreal baseScale = targetGraphDock->graphView->current_scale;
     qreal w = targetGraphDock->graphView->viewport()->width() * curScale / baseScale;
     qreal h = targetGraphDock->graphView->viewport()->height() * curScale / baseScale;
-    int graph_offset_x = targetGraphDock->graphView->offset_x;
-    int graph_offset_y = targetGraphDock->graphView->offset_y;
-    int overview_offset_x = overviewDock->graphView->offset_x;
-    int overview_offset_y = overviewDock->graphView->offset_y;
+    int graph_offset_x = targetGraphDock->graphView->offset.x();
+    int graph_offset_y = targetGraphDock->graphView->offset.y();
+    int overview_offset_x = overviewDock->graphView->offset.x();
+    int overview_offset_y = overviewDock->graphView->offset.y();
     int rangeRectX = graph_offset_x * curScale - overview_offset_x * curScale;
     int rangeRectY = graph_offset_y * curScale - overview_offset_y * curScale;
 
@@ -413,10 +413,10 @@ void MainWindow::adjustGraph()
     qreal curScale = overviewDock->graphView->current_scale;
     int rectx = overviewDock->graphView->rangeRect.x();
     int recty = overviewDock->graphView->rangeRect.y();
-    int overview_offset_x = overviewDock->graphView->offset_x;
-    int overview_offset_y = overviewDock->graphView->offset_y;
-    targetGraphDock->graphView->offset_x = rectx /curScale + overview_offset_x;
-    targetGraphDock->graphView->offset_y = recty /curScale + overview_offset_y;
+    int overview_offset_x = overviewDock->graphView->offset.x();
+    int overview_offset_y = overviewDock->graphView->offset.y();
+    targetGraphDock->graphView->offset.rx() = rectx /curScale + overview_offset_x;
+    targetGraphDock->graphView->offset.ry() = recty /curScale + overview_offset_y;
     targetGraphDock->graphView->viewport()->update();
 }
 

src/widgets/DisassemblerGraphView.cpp

@@ -65,10 +65,10 @@ DisassemblerGraphView::DisassemblerGraphView(QWidget *parent)
     // Zoom shortcuts
     QShortcut *shortcut_zoom_in = new QShortcut(QKeySequence(Qt::Key_Plus), this);
     shortcut_zoom_in->setContext(Qt::WidgetShortcut);
-    connect(shortcut_zoom_in, SIGNAL(activated()), this, SLOT(zoomIn()));
+    connect(shortcut_zoom_in, &QShortcut::activated, this, std::bind(&DisassemblerGraphView::zoom, this, QPointF(0.5, 0.5), 1));
     QShortcut *shortcut_zoom_out = new QShortcut(QKeySequence(Qt::Key_Minus), this);
     shortcut_zoom_out->setContext(Qt::WidgetShortcut);
-    connect(shortcut_zoom_out, SIGNAL(activated()), this, SLOT(zoomOut()));
+    connect(shortcut_zoom_out, &QShortcut::activated, this, std::bind(&DisassemblerGraphView::zoom, this, QPointF(0.5, 0.5), -1));
     QShortcut *shortcut_zoom_reset = new QShortcut(QKeySequence(Qt::Key_Equal), this);
     shortcut_zoom_reset->setContext(Qt::WidgetShortcut);
     connect(shortcut_zoom_reset, SIGNAL(activated()), this, SLOT(zoomReset()));
@@ -369,8 +369,8 @@ void DisassemblerGraphView::initFont()
 
 void DisassemblerGraphView::drawBlock(QPainter &p, GraphView::GraphBlock &block)
 {
-    int blockX = block.x - offset_x;
-    int blockY = block.y - offset_y;
+    int blockX = block.x - offset.x();
+    int blockY = block.y - offset.y();
 
     p.setPen(Qt::black);
     p.setBrush(Qt::gray);
@@ -695,19 +695,21 @@ void DisassemblerGraphView::onSeekChanged(RVA addr)
     }
 }
 
-void DisassemblerGraphView::zoomIn(QPoint mouse)
+void DisassemblerGraphView::zoom(QPointF mouseRelativePos, double velocity)
 {
-    Q_UNUSED(mouse);
-    current_scale += 0.1;
-    viewport()->update();
-    emit viewZoomed();
-}
+    mouseRelativePos.rx() *= size().width();
+    mouseRelativePos.ry() *= size().height();
+    mouseRelativePos /= current_scale;
 
-void DisassemblerGraphView::zoomOut(QPoint mouse)
-{
-    Q_UNUSED(mouse);
-    current_scale -= 0.1;
+    auto globalMouse = mouseRelativePos + offset;
+    mouseRelativePos *= current_scale;
+    current_scale *= std::pow(1.25, velocity);
     current_scale = std::max(current_scale, 0.3);
+    mouseRelativePos /= current_scale;
+
+    // Adjusting offset, so that zooming will be approaching to the cursor.
+    offset = globalMouse.toPoint() - mouseRelativePos.toPoint();
+
     viewport()->update();
     emit viewZoomed();
 }
@@ -968,13 +970,13 @@ void DisassemblerGraphView::wheelEvent(QWheelEvent *event)
     if (Qt::ControlModifier == event->modifiers()) {
         const QPoint numDegrees = event->angleDelta() / 8;
         if (!numDegrees.isNull()) {
-            const QPoint numSteps = numDegrees / 15;
-            QPoint mouse = event->globalPos();
-            if (numSteps.y() > 0) {
-                zoomIn(mouse);
-            } else if (numSteps.y() < 0) {
-                zoomOut(mouse);
-            }
+            int numSteps = numDegrees.y() / 15;
+
+            QPointF relativeMousePos = event->pos();
+            relativeMousePos.rx() /= size().width();
+            relativeMousePos.ry() /= size().height();
+
+            zoom(relativeMousePos, numSteps);
         }
         event->accept();
     } else {

src/widgets/DisassemblerGraphView.h

@@ -104,6 +104,7 @@ public:
     int getWidth() { return width; }
     int getHeight() { return height; }
     std::unordered_map<ut64, GraphBlock> getBlocks() { return blocks; }
+
 public slots:
     void refreshView();
     void colorsUpdatedSlot();
@@ -111,8 +112,7 @@ public slots:
     void onSeekChanged(RVA addr);
     void toggleSync();
 
-    void zoomIn(QPoint mouse = QPoint(0, 0));
-    void zoomOut(QPoint mouse = QPoint(0, 0));
+    void zoom(QPointF mouseRelativePos, double velocity);
     void zoomReset();
 
     void takeTrue();

src/widgets/GraphView.cpp

@@ -64,8 +64,8 @@ void GraphView::blockHelpEvent(GraphView::GraphBlock &block, QHelpEvent *event,
 
 bool GraphView::helpEvent(QHelpEvent *event)
 {
-    int x = event->pos().x() + offset_x;
-    int y = event->pos().y() - offset_y;
+    int x = event->pos().x() + offset.x();
+    int y = event->pos().y() - offset.y();
 
     for (auto &blockIt : blocks) {
         GraphBlock &block = blockIt.second;
@@ -373,7 +373,7 @@ QPolygonF GraphView::recalculatePolygon(QPolygonF polygon)
 {
     QPolygonF ret;
     for (int i = 0; i < polygon.size(); i++) {
-        ret << QPointF(polygon[i].x() - offset_x, polygon[i].y() - offset_y);
+        ret << QPointF(polygon[i].x() - offset.x(), polygon[i].y() - offset.y());
     }
     return ret;
 }
@@ -409,10 +409,10 @@ void GraphView::paintEvent(QPaintEvent *event)
         qreal blockHeight = block.height * current_scale;
 
         // Check if block is visible by checking if block intersects with view area
-        if (offset_x * current_scale < blockX + blockWidth
-                && blockX < offset_x * current_scale + render_width
-                && offset_y * current_scale < blockY + blockHeight
-                && blockY < offset_y * current_scale + render_height) {
+        if (offset.x() * current_scale < blockX + blockWidth
+                && blockX < offset.x() * current_scale + render_width
+                && offset.y() * current_scale < blockY + blockHeight
+                && blockY < offset.y() * current_scale + render_height) {
             drawBlock(p, block);
         }
 
@@ -696,14 +696,14 @@ void GraphView::center()
 
 void GraphView::centerX()
 {
-    offset_x = -((viewport()->width() - width * current_scale) / 2);
-    offset_x /= current_scale;
+    offset.rx() = -((viewport()->width() - width * current_scale) / 2);
+    offset.rx() /= current_scale;
 }
 
 void GraphView::centerY()
 {
-    offset_y = -((viewport()->height() - height * current_scale) / 2);
-    offset_y /= current_scale;
+    offset.ry() = -((viewport()->height() - height * current_scale) / 2);
+    offset.ry() /= current_scale;
 }
 
 void GraphView::showBlock(GraphBlock &block)
@@ -717,12 +717,12 @@ void GraphView::showBlock(GraphBlock *block)
         centerX();
     } else {
         int render_width = viewport()->width() / current_scale;
-        offset_x = block->x - ((render_width - block->width) / 2);
+        offset.rx() = block->x - ((render_width - block->width) / 2);
     }
     if (height * current_scale <= viewport()->height()) {
         centerY();
     } else {
-        offset_y = block->y - 30;
+        offset.ry() = block->y - 30;
     }
     blockTransitionedTo(block);
     viewport()->update();
@@ -763,8 +763,8 @@ bool GraphView::checkPointClicked(QPointF &point, int x, int y, bool above_y)
 // Mouse events
 void GraphView::mousePressEvent(QMouseEvent *event)
 {
-    int x = event->pos().x() / current_scale + offset_x;
-    int y = event->pos().y() / current_scale + offset_y;
+    int x = event->pos().x() / current_scale + offset.x();
+    int y = event->pos().y() / current_scale + offset.y();
 
     // Check if a block was clicked
     for (auto &blockIt : blocks) {
@@ -819,8 +819,8 @@ void GraphView::mousePressEvent(QMouseEvent *event)
 void GraphView::mouseMoveEvent(QMouseEvent *event)
 {
     if (scroll_mode) {
-        offset_x += (scroll_base_x - event->x()) / current_scale;
-        offset_y += (scroll_base_y - event->y()) / current_scale;
+        offset.rx() += (scroll_base_x - event->x()) / current_scale;
+        offset.ry() += (scroll_base_y - event->y()) / current_scale;
         scroll_base_x = event->x();
         scroll_base_y = event->y();
         viewport()->update();
@@ -829,8 +829,8 @@ void GraphView::mouseMoveEvent(QMouseEvent *event)
 
 void GraphView::mouseDoubleClickEvent(QMouseEvent *event)
 {
-    int x = event->pos().x() / current_scale + offset_x;
-    int y = event->pos().y() / current_scale + offset_y;
+    int x = event->pos().x() / current_scale + offset.x();
+    int y = event->pos().y() / current_scale + offset.y();
 
     // Check if a block was clicked
     for (auto &blockIt : blocks) {
@@ -865,9 +865,11 @@ void GraphView::mouseReleaseEvent(QMouseEvent *event)
 
 void GraphView::wheelEvent(QWheelEvent *event)
 {
-    const QPoint delta = -event->angleDelta();
-    offset_x += delta.x() / current_scale;
-    offset_y += delta.y() / current_scale;
+    QPoint delta = -event->angleDelta();
+
+    delta /= current_scale;
+    offset += delta;
+
     viewport()->update();
     event->accept();
 }

src/widgets/GraphView.h

@@ -101,8 +101,7 @@ public:
     // Zoom data
     qreal current_scale = 1.0;
 
-    int offset_x = 0;
-    int offset_y = 0;
+    QPoint offset = QPoint(0, 0);
 
     /**
      * @brief flag to control if the cached pixmap should be used

src/widgets/OverviewView.cpp

@@ -44,8 +44,8 @@ void OverviewView::refreshView()
 
 void OverviewView::drawBlock(QPainter &p, GraphView::GraphBlock &block)
 {
-    int blockX = block.x - offset_x;
-    int blockY = block.y - offset_y;
+    int blockX = block.x - offset.x();
+    int blockY = block.y - offset.y();
 
     p.setPen(Qt::black);
     p.setBrush(Qt::gray);