Drag n drop (#223)

Added drop interface for image files, images, and text, dragged from other applications.  (#153,#223)

- Lock aspect ration on new image objects by default
- Communicate context menu click location to paste actions

glabels/LabelEditor.cpp

@@ -38,6 +38,7 @@
 #include "model/Markup.h"
 #include "model/Settings.h"
 
+#include <QMimeData>
 #include <QMouseEvent>
 #include <QtMath>
 #include <QtDebug>
@@ -105,6 +106,7 @@ namespace glabels
 
 		setMouseTracking( true );
 		setFocusPolicy(Qt::StrongFocus);
+		setAcceptDrops( true );
 
 		connect( model::Settings::instance(), SIGNAL(changed()), this, SLOT(onSettingsChanged()) );
 		onSettingsChanged();
@@ -590,7 +592,7 @@ namespace glabels
 				//
 				if ( mState == IdleState )
 				{
-					emit contextMenuActivate();
+					emit contextMenuActivate( model::Point( xWorld, yWorld ) );
 				}
 			}
 		}
@@ -621,7 +623,7 @@ namespace glabels
 			/*
 			 * Emit signal regardless of mode
 			 */
-			emit pointerMoved( xWorld, yWorld );
+			emit pointerMoved( model::Point( xWorld, yWorld ) );
 
 
 			/*
@@ -1027,6 +1029,85 @@ namespace glabels
 	}
 
 
+	//
+	// Handle drag enter event
+	//
+	void LabelEditor::dragEnterEvent( QDragEnterEvent *event )
+	{
+		if ( event->mimeData()->hasUrls()   ||
+		     event->mimeData()->hasImage()  ||
+		     event->mimeData()->hasText() )
+		{
+			event->acceptProposedAction();
+		}
+		else
+		{
+			event->ignore();
+		}
+	}
+
+
+	//
+	// Handle drag move event
+	//
+	void LabelEditor::dragMoveEvent( QDragMoveEvent *event )
+	{
+		if ( event->mimeData()->hasUrls()   ||
+		     event->mimeData()->hasImage()  ||
+		     event->mimeData()->hasText() )
+		{
+			event->acceptProposedAction();
+		}
+		else
+		{
+			event->ignore();
+		}
+	}
+
+
+	//
+	// Handle drop event
+	//
+	void LabelEditor::dropEvent( QDropEvent *event )
+	{
+		/*
+		 * Transform to label coordinates
+		 */
+		QTransform transform;
+
+		transform.scale( mScale, mScale );
+		transform.translate( mX0.pt(), mY0.pt() );
+
+		QPointF pWorld = transform.inverted().map( event->position() );
+		auto xWorld = model::Distance::pt( pWorld.x() );
+		auto yWorld = model::Distance::pt( pWorld.y() );
+		auto p = model::Point( xWorld, yWorld );
+
+		if ( event->mimeData()->hasUrls() )
+		{
+			mUndoRedoModel->checkpoint( tr("Drop") );
+			mModel->pasteAsUrls( event->mimeData(), p );
+			event->acceptProposedAction();
+		}
+		else if ( event->mimeData()->hasImage() )
+		{
+			mUndoRedoModel->checkpoint( tr("Drop") );
+			mModel->pasteAsImage( event->mimeData(), p );
+			event->acceptProposedAction();
+		}
+		else if ( event->mimeData()->hasText() )
+		{
+			mUndoRedoModel->checkpoint( tr("Drop") );
+			mModel->pasteAsText( event->mimeData(), p );
+			event->acceptProposedAction();
+		}
+		else
+		{
+			event->ignore();
+		}
+	}
+
+
 	///
 	/// Draw Background Layer
 	///
@@ -1283,4 +1364,5 @@ namespace glabels
 		emit zoomChanged();
 	}
 
+
 } // namespace glabels

glabels/LabelEditor.h

@@ -57,9 +57,9 @@ namespace glabels
 		// Signals
 		/////////////////////////////////////
 	signals:
-		void contextMenuActivate();
+		void contextMenuActivate( model::Point p );
 		void zoomChanged();
-		void pointerMoved( const model::Distance& x, const model::Distance& y );
+		void pointerMoved( model::Point p );
 		void pointerExited();
 		void modeChanged();
 
@@ -126,6 +126,9 @@ namespace glabels
 		void leaveEvent( QEvent* event ) override;
 		void keyPressEvent( QKeyEvent* event ) override;
 		void paintEvent( QPaintEvent* event ) override;
+		void dragEnterEvent( QDragEnterEvent *event ) override;
+		void dragMoveEvent( QDragMoveEvent *event ) override;
+		void dropEvent( QDropEvent *event ) override;
 
 
 		/////////////////////////////////////

glabels/MainWindow.cpp

@@ -196,8 +196,8 @@ namespace glabels
 		connect( model::Settings::instance(), SIGNAL(changed()), this, SLOT(onSettingsChanged()) );
 		connect( QApplication::clipboard(), SIGNAL(dataChanged()), this, SLOT(clipboardChanged()) );
 #if 0
-		connect( mLabelEditor, SIGNAL(pointerMoved(double, double)),
-		         this, SLOT(onPointerMoved(double, double)) );
+		connect( mLabelEditor, SIGNAL(pointerMoved(model::Point)),
+		         this, SLOT(onPointerMoved(modelPoint)) );
 		connect( mLabelEditor, SIGNAL(pointerExited()), this, SLOT(onPointerExit()) );
 #endif
 
@@ -253,7 +253,7 @@ namespace glabels
 		manageActions();
 		setTitle();
 
-		connect( mLabelEditor, SIGNAL(contextMenuActivate()), this, SLOT(onContextMenuActivate()) );
+		connect( mLabelEditor, SIGNAL(contextMenuActivate(model::Point)), this, SLOT(onContextMenuActivate(model::Point)) );
 		connect( mModel, SIGNAL(nameChanged()), this, SLOT(onNameChanged()) );
 		connect( mModel, SIGNAL(modifiedChanged()), this, SLOT(onModifiedChanged()) );
 		connect( mModel, SIGNAL(selectionChanged()), this, SLOT(onSelectionChanged()) );
@@ -611,7 +611,7 @@ namespace glabels
 		contextPasteAction = new QAction( tr("&Paste"), this );
 		contextPasteAction->setIcon( Icons::EditPaste() );
 		contextPasteAction->setStatusTip( tr("Paste the clipboard") );
-		connect( contextPasteAction, SIGNAL(triggered()), this, SLOT(editPaste()) );
+		connect( contextPasteAction, SIGNAL(triggered()), this, SLOT(editContextPaste()) );
 
 		contextDeleteAction = new QAction( tr("&Delete"), this );
 		contextDeleteAction->setIcon( QIcon::fromTheme( "edit-delete" ) );
@@ -1345,7 +1345,21 @@ namespace glabels
 	void MainWindow::editPaste()
 	{
 		mUndoRedoModel->checkpoint( tr("Paste") );
-		mModel->paste();
+		mModel->paste( model::Point() );
+	}
+
+
+	///
+	/// Edit->Paste Action (from context menu)
+	///
+	void MainWindow::editContextPaste()
+	{
+		// Extract original context menu click location
+		auto *action = qobject_cast<QAction *>(sender());
+		auto p = action->data().value<model::Point>();
+
+		mUndoRedoModel->checkpoint( tr("Paste") );
+		mModel->paste( p );
 	}
 
 
@@ -1708,8 +1722,13 @@ namespace glabels
 	///
 	/// Context Menu Activation
 	///
-	void MainWindow::onContextMenuActivate()
+	void MainWindow::onContextMenuActivate( model::Point p )
 	{
+		// Save click location for potential paste action
+		QVariant variant;
+		variant.setValue( p );
+		contextPasteAction->setData( variant );
+
 		if ( mModel->isSelectionEmpty() )
 		{
 			noSelectionContextMenu->popup( QCursor::pos() );
@@ -1736,10 +1755,12 @@ namespace glabels
 	///
 	/// Pointer moved: update Cursor Information in Status Bar
 	///
-	void MainWindow::onPointerMoved( double x, double y )
+	void MainWindow::onPointerMoved( model::Point p )
 	{
-		/* TODO: convert x,y to locale units and set precision accordingly. */
-		cursorInfoLabel->setText( QString( "%1, %2" ).arg(x).arg(y) );
+		/* TODO: set precision accordingly. */
+		auto units = model::Settings::units();
+		cursorInfoLabel->setText( QString( "%1, %2" ).arg( p.x().toString(units) )
+		                                             .arg( p.y().toString(units) ) );
 	}
 
 

glabels/MainWindow.h

@@ -109,6 +109,7 @@ namespace glabels
 		void editCut();
 		void editCopy();
 		void editPaste();
+		void editContextPaste();
 		void editDelete();
 		void editSelectAll();
 		void editUnSelectAll();
@@ -150,10 +151,10 @@ namespace glabels
 		void helpReportBug();
 		void helpAbout();
 
-		void onContextMenuActivate();
+		void onContextMenuActivate( model::Point );
 
 		void onZoomChanged();
-		void onPointerMoved( double, double );
+		void onPointerMoved( model::Point );
 		void onPointerExit();
 
 		void onNameChanged();