From ffd35cbce3b5454d3ceaa2277129e218a3b39ffa Mon Sep 17 00:00:00 2001
From: Uwe Kindler <uwe_kindler@web.de>
Date: Mon, 16 Dec 2019 11:10:59 +0100
Subject: [PATCH] Added support for canceling non opaque docking with escape
 key, fixed state of non opaque docking when switching applications (if
 application becomes inactive)

---
 src/DockAreaTabBar.cpp  | 10 ++++++++--
 src/DockWidgetTab.cpp   |  8 +++++++-
 src/FloatingOverlay.cpp | 39 +++++++++++++++++++++++++++++++++++++++
 src/FloatingOverlay.h   | 12 ++++++++++++
 4 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/src/DockAreaTabBar.cpp b/src/DockAreaTabBar.cpp
index ed8e4e0..33a4e88 100644
--- a/src/DockAreaTabBar.cpp
+++ b/src/DockAreaTabBar.cpp
@@ -201,8 +201,9 @@ void CDockAreaTabBar::mouseReleaseEvent(QMouseEvent* ev)
 void CDockAreaTabBar::mouseMoveEvent(QMouseEvent* ev)
 {
 	QScrollArea::mouseMoveEvent(ev);
-	if (ev->buttons() != Qt::LeftButton)
+	if (!(ev->buttons() & Qt::LeftButton) || d->isDraggingState(DraggingInactive))
 	{
+		d->DragState = DraggingInactive;
 		return;
 	}
 
@@ -276,7 +277,12 @@ IFloatingWidget* CDockAreaTabBar::makeAreaFloating(const QPoint& Offset, eDragSt
 	}
 	else
 	{
-		FloatingWidget = new CFloatingOverlay(d->DockArea);
+		auto w = new CFloatingOverlay(d->DockArea);
+		connect(w, &CFloatingOverlay::draggingCanceled, [=]()
+		{
+			d->DragState = DraggingInactive;
+		});
+		FloatingWidget = w;
 	}
 
     FloatingWidget->startFloating(Offset, Size, DragState, nullptr);
diff --git a/src/DockWidgetTab.cpp b/src/DockWidgetTab.cpp
index 1b86a8e..9e8abf6 100644
--- a/src/DockWidgetTab.cpp
+++ b/src/DockWidgetTab.cpp
@@ -151,7 +151,12 @@ struct DockWidgetTabPrivate
 		}
 		else
 		{
-			return new CFloatingOverlay(Widget);
+			auto w = new CFloatingOverlay(Widget);
+			_this->connect(w, &CFloatingOverlay::draggingCanceled, [=]()
+			{
+				DragState = DraggingInactive;
+			});
+			return w;
 		}
 	}
 };
@@ -246,6 +251,7 @@ bool DockWidgetTabPrivate::startFloating(eDragState DraggingState)
 	IFloatingWidget* FloatingWidget = nullptr;
 	bool OpaqueUndocking = CDockManager::configFlags().testFlag(CDockManager::OpaqueUndocking) ||
 		(DraggingFloatingWidget != DraggingState);
+
 	// If section widget has multiple tabs, we take only one tab
 	// If it has only one single tab, we can move the complete
 	// dock area into floating widget
diff --git a/src/FloatingOverlay.cpp b/src/FloatingOverlay.cpp
index 3e95250..b8a68b4 100644
--- a/src/FloatingOverlay.cpp
+++ b/src/FloatingOverlay.cpp
@@ -15,6 +15,7 @@
 #include <QEvent>
 #include <QApplication>
 #include <QPainter>
+#include <QKeyEvent>
 
 #include "DockWidget.h"
 #include "DockAreaWidget.h"
@@ -53,6 +54,17 @@ struct FloatingOverlayPrivate
 		Hidden = Value;
 		_this->update();
 	}
+
+	/**
+	 * Cancel dragging and emit the draggingCanceled event
+	 */
+	void cancelDragging()
+	{
+		emit _this->draggingCanceled();
+		DockManager->containerOverlay()->hideOverlay();
+		DockManager->dockAreaOverlay()->hideOverlay();
+		_this->close();
+	}
 };
 // struct LedArrayPanelPrivate
 
@@ -192,6 +204,9 @@ CFloatingOverlay::CFloatingOverlay(QWidget* Content, QWidget* parent) :
 		d->ContentPreviewPixmap = QPixmap(Content->size());
 		Content->render(&d->ContentPreviewPixmap);
 	}
+
+	connect(qApp, SIGNAL(applicationStateChanged(Qt::ApplicationState)),
+		SLOT(onApplicationStateChanged(Qt::ApplicationState)));
 }
 
 
@@ -335,6 +350,30 @@ void CFloatingOverlay::paintEvent(QPaintEvent* event)
 }
 
 
+//============================================================================
+void CFloatingOverlay::keyPressEvent(QKeyEvent *event)
+{
+	Super::keyPressEvent(event);
+	if (event->key() == Qt::Key_Escape)
+	{
+		d->cancelDragging();
+	}
+}
+
+
+//============================================================================
+void CFloatingOverlay::onApplicationStateChanged(Qt::ApplicationState state)
+{
+	if (state != Qt::ApplicationActive)
+	{
+		disconnect(qApp, SIGNAL(applicationStateChanged(Qt::ApplicationState)),
+			this, SLOT(onApplicationStateChanged(Qt::ApplicationState)));
+		d->cancelDragging();
+	}
+}
+
+
+
 
 } // namespace ads
 
diff --git a/src/FloatingOverlay.h b/src/FloatingOverlay.h
index d218c92..c9af8c7 100644
--- a/src/FloatingOverlay.h
+++ b/src/FloatingOverlay.h
@@ -32,6 +32,9 @@ private:
 	FloatingOverlayPrivate* d;
 	friend class FloatingOverlayPrivate;
 
+private slots:
+	void onApplicationStateChanged(Qt::ApplicationState state);
+
 protected:
 	/**
 	 * Updates the drop overlays
@@ -43,6 +46,8 @@ protected:
 	 */
 	virtual void paintEvent(QPaintEvent *e) override;
 
+	virtual void keyPressEvent(QKeyEvent *event) override;
+
 	/**
 	 * The content is a DockArea or a DockWidget
 	 */
@@ -84,6 +89,13 @@ public: // implements IFloatingWidget -----------------------------------------
 	 * of the assigned Content widget
 	 */
 	virtual void finishDragging() override;
+
+signals:
+	/**
+	 * This signal is emitted, if dragging has been canceled by escape key
+	 * or by active application switching via task manager
+	 */
+	void draggingCanceled();
 };