Attachment 520 Details for Bug 1056 – Partial patch towards using QGestureEvents

[patch] Partial patch towards using QGestureEvents

0003-Partial-progress-towards-using-the-Qt-gesture-recogn.patch (text/plain), 4.64 KB, created by Ryan Govostes on 2019-03-20 05:39:46 CET

(hide)

Description:

Filename:

MIME Type:

Creator: Ryan Govostes

Created: 2019-03-20 05:39:46 CET

Size: 4.64 KB

patch

obsolete

>From 3ec969a001f1c840e3a3d199b8224865ff4990ff Mon Sep 17 00:00:00 2001
>From: Ryan Govostes <rgovostes+git@gmail.com>
>Date: Wed, 20 Mar 2019 00:19:45 -0400
>Subject: [PATCH 3/3] Partial progress towards using the Qt gesture recognition
> API
>
>---
> pv/views/trace/viewport.cpp | 71 ++++++++++++++++++-------------------
> pv/views/trace/viewport.hpp | 16 +++++----
> 2 files changed, 44 insertions(+), 43 deletions(-)
>
>diff --git a/pv/views/trace/viewport.cpp b/pv/views/trace/viewport.cpp
>index 44c912a..d1522e0 100644
>--- a/pv/views/trace/viewport.cpp
>+++ b/pv/views/trace/viewport.cpp
>@@ -49,11 +49,14 @@ namespace views {
> namespace trace {
> 
> Viewport::Viewport(View &parent) :
>-	ViewWidget(parent),
>-	pinch_zoom_active_(false)
>+	ViewWidget(parent)
> {
> 	setAutoFillBackground(true);
> 	setBackgroundRole(QPalette::Base);
>+
>+	// Register for gestures
>+	grabGesture(Qt::PanGesture);
>+	grabGesture(Qt::PinchGesture);
> }
> 
> shared_ptr<ViewItem> Viewport::get_mouse_over_item(const QPoint &pt)
>@@ -108,49 +111,43 @@ vector< shared_ptr<ViewItem> > Viewport::items()
> 	return items;
> }
> 
>-bool Viewport::touch_event(QTouchEvent *event)
>+bool Viewport::event(QEvent *event)
> {
>-	QList<QTouchEvent::TouchPoint> touchPoints = event->touchPoints();
>-
>-	if (touchPoints.count() != 2) {
>-		pinch_zoom_active_ = false;
>-		return false;
>-	}
>+	if (event->type() == QEvent::Gesture)
>+		return gestureEvent(static_cast<QGestureEvent*>(event));
>+	return ViewWidget::event(event);
>+}
> 
>-	const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
>-	const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();
>+bool Viewport::gestureEvent(QGestureEvent *event)
>+{
>+	assert(event);
> 
>-	if (!pinch_zoom_active_ ||
>-	    (event->touchPointStates() & Qt::TouchPointPressed)) {
>-		pinch_offset0_ = (view_.offset() + view_.scale() * touchPoint0.pos().x()).convert_to<double>();
>-		pinch_offset1_ = (view_.offset() + view_.scale() * touchPoint1.pos().x()).convert_to<double>();
>-		pinch_zoom_active_ = true;
>-	}
>+	// Handle pinch-to-zoom gestures
>+	if (auto pinch = static_cast<QPinchGesture *>(event->gesture(Qt::PinchGesture))) {
>+		if (pinch->state() == Qt::GestureStarted) {
>+			gesture_start_scale_ = view_.scale();
>+			gesture_start_offset_ = view_.offset();
>+		}
> 
>-	double w = touchPoint1.pos().x() - touchPoint0.pos().x();
>-	if (abs(w) >= 1.0) {
>-		const double scale =
>-			fabs((pinch_offset1_ - pinch_offset0_) / w);
>-		double offset = pinch_offset0_ - touchPoint0.pos().x() * scale;
>-		if (scale > 0)
>-			view_.set_scale_offset(scale, offset);
>+		// FIXME: Make pinch-to-zoom more intuitive
>+		auto flags = QPinchGesture::ScaleFactorChanged | QPinchGesture::CenterPointChanged;
>+		if (pinch->changeFlags() & flags) {
>+			double scale = gesture_start_scale_ * pinch->totalScaleFactor();
>+			double xdelta = pinch->centerPoint().x() - pinch->startCenterPoint().x();
>+			pv::util::Timestamp offset = gesture_start_offset_ + xdelta * scale;
>+			if (scale > 0.0) {
>+				view_.set_scale_offset(scale, offset);
>+			}
>+		}
>+		return true;
> 	}
> 
>-	if (event->touchPointStates() & Qt::TouchPointReleased) {
>-		pinch_zoom_active_ = false;
>-
>-		if (touchPoint0.state() & Qt::TouchPointReleased) {
>-			// Primary touch released
>-			drag_release();
>-		} else {
>-			// Update the mouse down fields so that continued
>-			// dragging with the primary touch will work correctly
>-			mouse_down_point_ = touchPoint0.pos().toPoint();
>-			drag();
>-		}
>+	if (auto pan = static_cast<QPanGesture *>(event->gesture(Qt::PanGesture))) {
>+		// TODO: Implement
>+		return true;
> 	}
> 
>-	return true;
>+	return false;
> }
> 
> void Viewport::paintEvent(QPaintEvent*)
>diff --git a/pv/views/trace/viewport.hpp b/pv/views/trace/viewport.hpp
>index 1b77a0d..d633798 100644
>--- a/pv/views/trace/viewport.hpp
>+++ b/pv/views/trace/viewport.hpp
>@@ -22,9 +22,9 @@
> 
> #include <boost/optional.hpp>
> 
>+#include <QGestureEvent>
> #include <QPoint>
> #include <QTimer>
>-#include <QTouchEvent>
> 
> #include "pv/util.hpp"
> #include "viewwidget.hpp"
>@@ -87,10 +87,15 @@ private:
> 	vector< shared_ptr<ViewItem> > items();
> 
> 	/**
>-	 * Handles touch begin update and end events.
>+	 * Main event handler; dispatches gesture events to gestureEvent().
>+	 */
>+	bool event(QEvent *event);
>+
>+	/**
>+	 * Handles gesture-related events.
> 	 * @param e the event that triggered this handler.
> 	 */
>-	bool touch_event(QTouchEvent *event);
>+	bool gestureEvent(QGestureEvent *event);
> 
> private:
> 	void paintEvent(QPaintEvent *event);
>@@ -102,9 +107,8 @@ private:
> 	boost::optional<pv::util::Timestamp> drag_offset_;
> 	int drag_v_offset_;
> 
>-	double pinch_offset0_;
>-	double pinch_offset1_;
>-	bool pinch_zoom_active_;
>+	double gesture_start_scale_;
>+	pv::util::Timestamp gesture_start_offset_;
> };
> 
> } // namespace trace
>-- 
>2.20.1
>

Actions: View

Attachments on bug 1056: 518 | 519 | 520