Add `event::Context::consumed`.

include/event.hpp

@@ -17,8 +17,12 @@ namespace event {
 
 /** A per-event state shared and writable by all widgets that recursively handle an event. */
 struct Context {
-	widget::Widget *target = NULL;
+	/** Whether the event should continue recursing to children Widgets. */
 	bool propagating = true;
+	/** Whether the event has been consumed by an event handler and no more handlers should consume the event. */
+	bool consumed = false;
+	/** The widget that responded to the event. */
+	widget::Widget *target = NULL;
 };
 
 
@@ -29,30 +33,36 @@ struct Base {
 	/** Prevents the event from being handled by more Widgets.
 	*/
 	void stopPropagating() const {
-		if (context)
-			context->propagating = false;
+		if (!context) return;
+		context->propagating = false;
 	}
 	bool isPropagating() const {
-		if (context)
-			return context->propagating;
-		return true;
+		if (!context) return true;
+		return context->propagating;
 	}
 	/** Tells the event handler that a particular Widget consumed the event.
 	You usually want to stop propagation as well, so call consume() instead.
 	*/
 	void setTarget(widget::Widget *w) const {
-		if (context)
-			context->target = w;
+		if (!context) return;
+		context->target = w;
 	}
 	widget::Widget *getTarget() const {
-		if (context)
-			return context->target;
-		return NULL;
+		if (!context) return NULL;
+		return context->target;
 	}
-	/** Sets the target Widget and stops propagation. */
+	/** Sets the target Widget and stops propagating.
+	A NULL Widget may be passed to consume but not set a target.
+	*/
 	void consume(widget::Widget *w) const {
-		setTarget(w);
-		stopPropagating();
+		if (!context) return;
+		context->propagating = false;
+		context->consumed = true;
+		context->target = w;
+	}
+	bool isConsumed() const {
+		if (!context) return false;
+		return context->consumed;
 	}
 };
 
@@ -150,7 +160,7 @@ struct Leave : Base {
 };
 
 
-/** Occurs when a Widget begins consuming the Button press event.
+/** Occurs when a Widget begins consuming the Button press event for the left mouse button.
 Must consume to set the widget as selected.
 */
 struct Select : Base {
@@ -177,22 +187,27 @@ struct SelectText : Base, TextBase {
 };
 
 
+struct DragBase : Base {
+	/** The mouse button held during the drag. */
+	int button;
+};
+
 /** Occurs when a Widget begins being dragged.
 Must consume to set the widget as dragged.
 */
-struct DragStart : Base {
+struct DragStart : DragBase {
 };
 
 
 /** Occurs when a Widget stops being dragged by releasing the mouse button.
 */
-struct DragEnd : Base {
+struct DragEnd : DragBase {
 };
 
 
 /** Occurs every frame on the dragged Widget.
 */
-struct DragMove : Base {
+struct DragMove : DragBase {
 	/** Change in mouse position since the last frame. Can be zero. */
 	math::Vec mouseDelta;
 };
@@ -201,7 +216,7 @@ struct DragMove : Base {
 /** Occurs every frame when the mouse is hovering over a Widget while another Widget (possibly the same one) is being dragged.
 Recurses until consumed.
 */
-struct DragHover : Base, PositionBase {
+struct DragHover : DragBase, PositionBase {
 	/** The dragged widget */
 	widget::Widget *origin = NULL;
 	/** Change in mouse position since the last frame. Can be zero. */
@@ -211,7 +226,7 @@ struct DragHover : Base, PositionBase {
 /** Occurs when the mouse enters a Widget while dragging.
 Must consume to set the widget as drag-hovered.
 */
-struct DragEnter : Base {
+struct DragEnter : DragBase {
 	/** The dragged widget */
 	widget::Widget *origin = NULL;
 };
@@ -219,7 +234,7 @@ struct DragEnter : Base {
 
 /** Occurs when the mouse leaves a Widget while dragging.
 */
-struct DragLeave : Base {
+struct DragLeave : DragBase {
 	/** The dragged widget */
 	widget::Widget *origin = NULL;
 };
@@ -227,7 +242,7 @@ struct DragLeave : Base {
 
 /** Occurs when the mouse button is released over a Widget while dragging.
 */
-struct DragDrop : Base {
+struct DragDrop : DragBase {
 	/** The dragged widget */
 	widget::Widget *origin = NULL;
 };
@@ -308,6 +323,7 @@ struct State {
 	*/
 	widget::Widget *hoveredWidget = NULL;
 	widget::Widget *draggedWidget = NULL;
+	int dragButton = 0;
 	widget::Widget *dragHoveredWidget = NULL;
 	widget::Widget *selectedWidget = NULL;
 	/** For double-clicking */
@@ -315,7 +331,7 @@ struct State {
 	widget::Widget *lastClickedWidget = NULL;
 
 	void setHovered(widget::Widget *w);
-	void setDragged(widget::Widget *w);
+	void setDragged(widget::Widget *w, int button);
 	void setDragHovered(widget::Widget *w);
 	void setSelected(widget::Widget *w);
 	/** Prepares a widget for deletion */

include/widget/OpaqueWidget.hpp

@@ -7,6 +7,7 @@ namespace widget {
 
 
 /** A Widget that stops propagation of all recursive PositionEvents but gives a chance for children to consume first.
+Also consumes Hover and Button for left-clicks.
 Remember to call these methods in your subclass if you wish to preserve default OpaqueWidget behavior.
 */
 struct OpaqueWidget : Widget {
@@ -14,15 +15,17 @@ struct OpaqueWidget : Widget {
 		Widget::onHover(e);
 		e.stopPropagating();
 		// Consume if not consumed by child
-		if (!e.getTarget())
-			e.setTarget(this);
+		if (!e.isConsumed())
+			e.consume(this);
 	}
 	void onButton(const event::Button &e) override {
 		Widget::onButton(e);
 		e.stopPropagating();
-		// Consume if not consumed by child
-		if (!e.getTarget())
-			e.setTarget(this);
+		if (e.button == GLFW_MOUSE_BUTTON_LEFT) {
+			// Consume if not consumed by child
+			if (!e.isConsumed())
+				e.consume(this);
+		}
 	}
 	void onHoverKey(const event::HoverKey &e) override {
 		Widget::onHoverKey(e);

src/event.cpp

@@ -27,22 +27,26 @@ void State::setHovered(widget::Widget *w) {
 	}
 }
 
-void State::setDragged(widget::Widget *w) {
+void State::setDragged(widget::Widget *w, int button) {
 	if (w == draggedWidget)
 		return;
 
 	if (draggedWidget) {
 		// DragEnd
 		DragEnd eDragEnd;
+		eDragEnd.button = dragButton;
 		draggedWidget->onDragEnd(eDragEnd);
 		draggedWidget = NULL;
 	}
 
+	dragButton = button;
+
 	if (w) {
 		// DragStart
 		Context cDragStart;
 		DragStart eDragStart;
 		eDragStart.context = &cDragStart;
+		eDragStart.button = dragButton;
 		w->onDragStart(eDragStart);
 		draggedWidget = cDragStart.target;
 	}
@@ -55,6 +59,7 @@ void State::setDragHovered(widget::Widget *w) {
 	if (dragHoveredWidget) {
 		// DragLeave
 		DragLeave eDragLeave;
+		eDragLeave.button = dragButton;
 		eDragLeave.origin = draggedWidget;
 		dragHoveredWidget->onDragLeave(eDragLeave);
 		dragHoveredWidget = NULL;
@@ -65,6 +70,7 @@ void State::setDragHovered(widget::Widget *w) {
 		Context cDragEnter;
 		DragEnter eDragEnter;
 		eDragEnter.context = &cDragEnter;
+		eDragEnter.button = dragButton;
 		eDragEnter.origin = draggedWidget;
 		w->onDragEnter(eDragEnter);
 		dragHoveredWidget = cDragEnter.target;
@@ -94,7 +100,7 @@ void State::setSelected(widget::Widget *w) {
 
 void State::finalizeWidget(widget::Widget *w) {
 	if (hoveredWidget == w) setHovered(NULL);
-	if (draggedWidget == w) setDragged(NULL);
+	if (draggedWidget == w) setDragged(NULL, 0);
 	if (dragHoveredWidget == w) setDragHovered(NULL);
 	if (selectedWidget == w) setSelected(NULL);
 	if (lastClickedWidget == w) lastClickedWidget = NULL;
@@ -112,24 +118,25 @@ void State::handleButton(math::Vec pos, int button, int action, int mods) {
 	rootWidget->onButton(eButton);
 	widget::Widget *clickedWidget = cButton.target;
 
-	if (button == GLFW_MOUSE_BUTTON_LEFT) {
-		if (action == GLFW_PRESS) {
-			setDragged(clickedWidget);
-		}
-
-		if (action == GLFW_RELEASE) {
-			setDragHovered(NULL);
+	if (action == GLFW_PRESS) {
+		setDragged(clickedWidget, button);
+	}
 
-			if (clickedWidget && draggedWidget) {
-				// DragDrop
-				DragDrop eDragDrop;
-				eDragDrop.origin = draggedWidget;
-				clickedWidget->onDragDrop(eDragDrop);
-			}
+	if (action == GLFW_RELEASE) {
+		setDragHovered(NULL);
 
-			setDragged(NULL);
+		if (clickedWidget && draggedWidget) {
+			// DragDrop
+			DragDrop eDragDrop;
+			eDragDrop.button = dragButton;
+			eDragDrop.origin = draggedWidget;
+			clickedWidget->onDragDrop(eDragDrop);
 		}
 
+		setDragged(NULL, 0);
+	}
+
+	if (button == GLFW_MOUSE_BUTTON_LEFT) {
 		if (action == GLFW_PRESS) {
 			setSelected(clickedWidget);
 		}
@@ -159,6 +166,7 @@ void State::handleHover(math::Vec pos, math::Vec mouseDelta) {
 	if (draggedWidget) {
 		// DragMove
 		DragMove eDragMove;
+		eDragMove.button = dragButton;
 		eDragMove.mouseDelta = mouseDelta;
 		draggedWidget->onDragMove(eDragMove);
 
@@ -166,6 +174,7 @@ void State::handleHover(math::Vec pos, math::Vec mouseDelta) {
 		Context cDragHover;
 		DragHover eDragHover;
 		eDragHover.context = &cDragHover;
+		eDragHover.button = dragButton;
 		eDragHover.pos = pos;
 		eDragHover.mouseDelta = mouseDelta;
 		eDragHover.origin = draggedWidget;