decorator: generalize include/decorator/window.h

This change makes it possible to reuse the generic window decorator
classes in include/decorator/ for decorators of a different structure.
E.g., instead of painting decorations on a single nitpicker session,
each window may paint its decorations into additional window-specific
nitpicker sessions.

repos/gems/src/app/decorator/texture_by_id.cc

@@ -1,5 +1,5 @@
 /*
- * \brief  Accessor for the default font
+ * \brief  Accessor for textures
  * \author Norman Feske
  * \date   2015-09-16
  */

repos/gems/src/app/decorator/window.cc

@@ -205,7 +205,35 @@ static bool attribute_has_value(Genode::Xml_node node,
 
 bool Decorator::Window::update(Genode::Xml_node window_node)
 {
-	bool updated = Window_base::update(window_node);
+	bool updated = false;
+
+	/*
+	 * Detect the need to bring the window to the top of the global
+	 * view stack.
+	 */
+	unsigned const topped_cnt = attribute(window_node, "topped", 0UL);
+	if (topped_cnt != _topped_cnt) {
+
+		_global_to_front               = true;
+		_topped_cnt                    = topped_cnt;
+		_nitpicker_stacking_up_to_date = false;
+
+		updated |= true;
+	}
+
+	/*
+	 * Detect geometry changes
+	 */
+	Rect new_geometry = rect_attribute(window_node);
+	if (new_geometry.p1() != geometry().p1()
+	 || new_geometry.p2() != geometry().p2()) {
+
+		geometry(new_geometry);
+
+		_nitpicker_views_up_to_date = false;
+
+		updated |= true;
+	}
 
 	_focused   = attribute_has_value(window_node, "focused",   "yes");
 	_has_alpha = attribute_has_value(window_node, "has_alpha", "yes");

repos/gems/src/app/decorator/window.h

@@ -29,6 +29,82 @@ class Decorator::Window : public Window_base
 {
 	private:
 
+		Nitpicker::Session_client &_nitpicker;
+
+		/*
+		 * Flag indicating that the current window position has been propagated
+		 * to the window's corresponding nitpicker views.
+		 */
+		bool _nitpicker_views_up_to_date = false;
+
+		/*
+		 * Flag indicating that the stacking position of the window within the
+		 * window stack has changed. The new stacking position must be
+		 * propagated to nitpicker.
+		 */
+		bool _nitpicker_stacking_up_to_date = false;
+
+		Nitpicker::Session::View_handle _neighbor;
+
+		struct Nitpicker_view
+		{
+			Nitpicker::Session_client      &_nitpicker;
+			Nitpicker::Session::View_handle _handle { _nitpicker.create_view() };
+
+			typedef Nitpicker::Session::Command Command;
+
+			Nitpicker_view(Nitpicker::Session_client &nitpicker, unsigned id = 0)
+			:
+				_nitpicker(nitpicker)
+			{
+				/*
+				 * We supply the window ID as label for the anchor view.
+				 */
+				if (id) {
+					char buf[128];
+					Genode::snprintf(buf, sizeof(buf), "%d", id);
+
+					_nitpicker.enqueue<Command::Title>(_handle, buf);
+				}
+			}
+
+			~Nitpicker_view()
+			{
+				_nitpicker.destroy_view(_handle);
+			}
+
+			Nitpicker::Session::View_handle handle() const { return _handle; }
+
+			void stack(Nitpicker::Session::View_handle neighbor)
+			{
+				_nitpicker.enqueue<Command::To_front>(_handle, neighbor);
+			}
+
+			void place(Rect rect)
+			{
+				_nitpicker.enqueue<Command::Geometry>(_handle, rect);
+				Point offset = Point(0, 0) - rect.p1();
+				_nitpicker.enqueue<Command::Offset>(_handle, offset);
+			}
+		};
+
+		Nitpicker_view _bottom_view { _nitpicker },
+		               _right_view  { _nitpicker },
+		               _left_view   { _nitpicker },
+		               _top_view    { _nitpicker };
+
+		Nitpicker_view _content_view { _nitpicker, id() };
+
+		static Border _init_border() {
+			return Border(_border_size + _title_height,
+			              _border_size, _border_size, _border_size); }
+
+		Border const _border { _init_border() };
+
+		bool _global_to_front = false;
+
+		unsigned _topped_cnt = 0;
+
 		Window_title _title;
 
 		bool _focused = false;
@@ -41,9 +117,6 @@ class Decorator::Window : public Window_base
 		static unsigned const _border_size = 4;
 		static unsigned const _title_height = 16;
 
-		static Border _border() {
-			return Border(_border_size + _title_height,
-			              _border_size, _border_size, _border_size); }
 
 		Color _bright = { 255, 255, 255, 64 };
 		Color _dark   = { 0, 0, 0, 127 };
@@ -54,7 +127,6 @@ class Decorator::Window : public Window_base
 
 		Area const _icon_size { 16, 16 };
 
-
 		/*
 		 * Intensity of the title-bar radient in percent. A value of 0 produces
 		 * no gradient. A value of 100 creates a gradient from white over
@@ -329,10 +401,78 @@ class Decorator::Window : public Window_base
 		Window(unsigned id, Nitpicker::Session_client &nitpicker,
 		       Animator &animator, Config const &config)
 		:
-			Window_base(id, nitpicker, _border()),
+			Window_base(id),
+			_nitpicker(nitpicker),
 			_animator(animator), _config(config)
 		{ }
 
+		void stack(Nitpicker::Session::View_handle neighbor) override
+		{
+			_neighbor = neighbor;
+			_nitpicker_stacking_up_to_date = false;
+		}
+
+		Nitpicker::Session::View_handle frontmost_view() const override
+		{
+			return _bottom_view.handle();
+		}
+
+		Rect outer_geometry() const override
+		{
+			return Rect(geometry().p1() - Point(_border.left,  _border.top),
+			            geometry().p2() + Point(_border.right, _border.bottom));
+		}
+
+		void border_rects(Rect *top, Rect *left, Rect *right, Rect *bottom) const
+		{
+			outer_geometry().cut(geometry(), top, left, right, bottom);
+		}
+
+		bool is_in_front_of(Window_base const &neighbor) const override
+		{
+			return _neighbor == neighbor.frontmost_view();
+		}
+
+		void update_nitpicker_views() override
+		{
+			if (!_nitpicker_views_up_to_date) {
+
+				/* update view positions */
+				Rect top, left, right, bottom;
+				border_rects(&top, &left, &right, &bottom);
+
+				_content_view.place(geometry());
+				_top_view    .place(top);
+				_left_view   .place(left);
+				_right_view  .place(right);
+				_bottom_view .place(bottom);
+
+				_nitpicker_views_up_to_date = true;
+			}
+
+			if (!_nitpicker_stacking_up_to_date) {
+
+				/*
+				 * Bring the view to the global top of the view stack if the
+				 * 'topped' counter changed. Otherwise, we refer to a
+				 * session-local neighbor for the restacking operation.
+				 */
+				Nitpicker::Session::View_handle neighbor = _neighbor;
+				if (_global_to_front) {
+					neighbor = Nitpicker::Session::View_handle();
+					_global_to_front = false;
+				}
+
+				_content_view.stack(neighbor);
+				_top_view.stack(_content_view.handle());
+				_left_view.stack(_top_view.handle());
+				_right_view.stack(_left_view.handle());
+				_bottom_view.stack(_right_view.handle());
+
+				_nitpicker_stacking_up_to_date = true;
+			}
+		}
+
 		void adapt_to_changed_config()
 		{
 			_base_color = _config.base_color(_title);

repos/os/include/decorator/window.h

@@ -85,11 +85,8 @@ class Decorator::Window_base : public Window_list::Element
 			virtual void draw_behind(Canvas_base &, Window_base const &, Rect) const = 0;
 		};
 
-
 	private:
 
-		Nitpicker::Session_client &_nitpicker;
-
 		/*
 		 * Geometry of content
 		 */
@@ -100,114 +97,22 @@ class Decorator::Window_base : public Window_list::Element
 		 */
 		unsigned const _id;
 
-		/*
-		 * Flag indicating that the current window position has been propagated
-		 * to the window's corresponding nitpicker views.
-		 */
-		bool _nitpicker_views_up_to_date = false;
-
-		/*
-		 * Flag indicating that the stacking position of the window within the
-		 * window stack has changed. The new stacking position must be
-		 * propagated to nitpicker.
-		 */
-		bool _nitpicker_stacking_up_to_date = false;
-
-		unsigned _topped_cnt = 0;
-
-		bool _global_to_front = false;
-
-		Nitpicker::Session::View_handle _neighbor;
-
-		Border const _border;
-
-		struct Nitpicker_view
-		{
-			Nitpicker::Session_client      &_nitpicker;
-			Nitpicker::Session::View_handle _handle { _nitpicker.create_view() };
-
-			typedef Nitpicker::Session::Command Command;
-
-			Nitpicker_view(Nitpicker::Session_client &nitpicker, unsigned id = 0)
-			:
-				_nitpicker(nitpicker)
-			{
-				/*
-				 * We supply the window ID as label for the anchor view.
-				 */
-				if (id) {
-					char buf[128];
-					Genode::snprintf(buf, sizeof(buf), "%d", id);
-
-					_nitpicker.enqueue<Command::Title>(_handle, buf);
-				}
-			}
-
-			~Nitpicker_view()
-			{
-				_nitpicker.destroy_view(_handle);
-			}
-
-			Nitpicker::Session::View_handle handle() const { return _handle; }
-
-			void stack(Nitpicker::Session::View_handle neighbor)
-			{
-				_nitpicker.enqueue<Command::To_front>(_handle, neighbor);
-			}
-
-			void place(Rect rect)
-			{
-				_nitpicker.enqueue<Command::Geometry>(_handle, rect);
-				Point offset = Point(0, 0) - rect.p1();
-				_nitpicker.enqueue<Command::Offset>(_handle, offset);
-			}
-		};
-
-		Nitpicker_view _bottom_view, _right_view, _left_view, _top_view;
-		Nitpicker_view _content_view;
-
 	public:
 
-		Window_base(unsigned id, Nitpicker::Session_client &nitpicker,
+		Window_base(unsigned id) : _id(id) { }
-		            Border border)
-		:
-			_nitpicker(nitpicker), _id(id), _border(border),
-			_bottom_view(nitpicker),
-			_right_view(nitpicker),
-			_left_view(nitpicker),
-			_top_view(nitpicker),
-			_content_view(nitpicker, _id)
-		{ }
-
-		void stack(Nitpicker::Session::View_handle neighbor)
-		{
-			_neighbor = neighbor;
-			_nitpicker_stacking_up_to_date = false;
-		}
-
-		Nitpicker::Session::View_handle frontmost_view() const
-		{
-			return _bottom_view.handle();
-		}
-
-		Rect outer_geometry() const
-		{
-			return Rect(_geometry.p1() - Point(_border.left,  _border.top),
-			            _geometry.p2() + Point(_border.right, _border.bottom));
-		}
-
-		void border_rects(Rect *top, Rect *left, Rect *right, Rect *bottom) const
-		{
-			outer_geometry().cut(_geometry, top, left, right, bottom);
-		}
 
 		unsigned long id()       const { return _id; }
 		Rect          geometry() const { return _geometry; }
 
-		bool is_in_front_of(Window_base const &neighbor) const
+		void geometry(Rect geometry) { _geometry = geometry; }
-		{
+
-			return _neighbor == neighbor.frontmost_view();
+		virtual Rect outer_geometry() const = 0;
-		}
+
+		virtual void stack(Nitpicker::Session::View_handle neighbor) = 0;
+
+		virtual Nitpicker::Session::View_handle frontmost_view() const = 0;
+
+		virtual bool is_in_front_of(Window_base const &neighbor) const = 0;
 
 		/**
 		 * Draw window elements
@@ -227,79 +132,9 @@ class Decorator::Window_base : public Window_list::Element
 		 * decorations haven't been redrawn already. If we updated the
 		 * nitpicker views at this point, we would reveal not-yet-drawn pixels.
 		 */
-		virtual bool update(Xml_node window_node)
+		virtual bool update(Xml_node window_node) = 0;
-		{
-			bool result = false;
 
-			/*
+		virtual void update_nitpicker_views() { }
-			 * Detect the need to bring the window to the top of the global
-			 * view stack.
-			 */
-			unsigned const topped_cnt = attribute(window_node, "topped", 0UL);
-			if (topped_cnt != _topped_cnt) {
-
-				_global_to_front               = true;
-				_topped_cnt                    = topped_cnt;
-				_nitpicker_stacking_up_to_date = false;
-
-				result = true;
-			}
-
-			/*
-			 * Detect geometry changes
-			 */
-			Rect new_geometry = rect_attribute(window_node);
-			if (new_geometry.p1() != _geometry.p1()
-			 || new_geometry.p2() != _geometry.p2()) {
-
-				_geometry = new_geometry;
-
-				_nitpicker_views_up_to_date = false;
-
-				result = true;
-			}
-			return result;
-		}
-
-		virtual void update_nitpicker_views()
-		{
-			if (!_nitpicker_views_up_to_date) {
-
-				/* update view positions */
-				Rect top, left, right, bottom;
-				border_rects(&top, &left, &right, &bottom);
-
-				_content_view.place(_geometry);
-				_top_view    .place(top);
-				_left_view   .place(left);
-				_right_view  .place(right);
-				_bottom_view .place(bottom);
-
-				_nitpicker_views_up_to_date = true;
-			}
-
-			if (!_nitpicker_stacking_up_to_date) {
-
-				/*
-				 * Bring the view to the global top of the view stack if the
-				 * 'topped' counter changed. Otherwise, we refer to a
-				 * session-local neighbor for the restacking operation.
-				 */
-				Nitpicker::Session::View_handle neighbor = _neighbor;
-				if (_global_to_front) {
-					neighbor = Nitpicker::Session::View_handle();
-					_global_to_front = false;
-				}
-
-				_content_view.stack(neighbor);
-				_top_view.stack(_content_view.handle());
-				_left_view.stack(_top_view.handle());
-				_right_view.stack(_left_view.handle());
-				_bottom_view.stack(_right_view.handle());
-
-				_nitpicker_stacking_up_to_date = true;
-			}
-		}
 
 		/**
 		 * Report information about element at specified position