From: Joel Holdsworth <redacted>
Date: Sat, 30 Jun 2012 12:49:56 +0000 (+0100)
Subject: Implemented dragging and zooming
X-Git-Tag: pulseview-0.1.0~329
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=1dd95c70180967864bd83d9679f3e9a6c2a4e383;p=pulseview.git

Implemented dragging and zooming
---

diff --git a/sigview.cpp b/sigview.cpp
index a8e85359..6a2b6204 100644
--- a/sigview.cpp
+++ b/sigview.cpp
@@ -130,35 +130,38 @@ void SigView::dataUpdated()
 	update();
 }
 
-void SigView::mouseMoveEvent(QMouseEvent *event)
+void SigView::mousePressEvent(QMouseEvent *event)
 {
 	assert(event);
+
+	_mouse_down_point = event->pos();
+	_mouse_down_offset = _offset;
 }
 
-void SigView::mousePressEvent(QMouseEvent *event)
+void SigView::mouseMoveEvent(QMouseEvent *event)
 {
 	assert(event);
+
+	if(event->buttons() & Qt::LeftButton)
+	{
+		_offset = _mouse_down_offset + (_mouse_down_point - event->pos()).x() * _scale;
+		update();
+	}
 }
 
 void SigView::mouseReleaseEvent(QMouseEvent *event)
 {
 	assert(event);
+}
 
-	const double cursor_offset = _offset + _scale * (double)event->x();
-
-	switch(event->button())
-	{
-	case Qt::LeftButton:
-		_scale *= 2.0 / 3.0;
-		break;
-
-	case Qt::RightButton:
-		_scale *= 3.0 / 2.0;
-		break;
-	}
-
-	_offset = cursor_offset - _scale * (double)event->x();
+void SigView::wheelEvent(QWheelEvent *event)
+{
+	assert(event);
 
+	const double x = event->x() - LabelMarginWidth;
+	const double cursor_offset = _offset + _scale * x;
+	_scale *= powf(3.0/2.0, -event->delta() / 120);
+	_offset = cursor_offset - _scale * x;
 	update();
 }
 
diff --git a/sigview.h b/sigview.h
index 34eeb959..d66898f4 100644
--- a/sigview.h
+++ b/sigview.h
@@ -55,9 +55,10 @@ protected:
 	void paintEvent(QPaintEvent *event);
 
 private:
-	void mouseMoveEvent(QMouseEvent *event);
 	void mousePressEvent(QMouseEvent *event);
+	void mouseMoveEvent(QMouseEvent *event);
 	void mouseReleaseEvent(QMouseEvent *event);
+	void wheelEvent(QWheelEvent *event);
 
 private:
 	void setupViewport(int width, int height);
@@ -72,6 +73,9 @@ private:
 
 	double _scale;
 	double _offset;
+
+	QPoint _mouse_down_point;
+	double _mouse_down_offset;
 };
 
 #endif // SIGVIEW_H