ActivityMonitor: remove double buffering and custom background drawing

Part of #15623.

Change-Id: Id6b7c13623e66d5b88ffc48766a5fe5ec4099b64
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2133
Reviewed-by: Stephan Aßmus <[email protected]>

src/apps/activitymonitor/ActivityView.cpp

@@ -553,7 +553,7 @@ const float kDraggerSize = 7;
 ActivityView::ActivityView(BRect frame, const char* name,
 		const BMessage* settings, uint32 resizingMode)
 	: BView(frame, name, resizingMode,
-		B_WILL_DRAW | B_FULL_UPDATE_ON_RESIZE | B_FRAME_EVENTS),
+		B_WILL_DRAW | B_SUBPIXEL_PRECISE | B_FULL_UPDATE_ON_RESIZE | B_FRAME_EVENTS),
 	fSourcesLock("data sources")
 {
 	_Init(settings);
@@ -598,7 +598,6 @@ ActivityView::ActivityView(BMessage* archive)
 
 ActivityView::~ActivityView()
 {
-	delete fOffscreen;
 	delete fSystemInfoHandler;
 }
 
@@ -609,7 +608,6 @@ ActivityView::_Init(const BMessage* settings)
 	fHistoryBackgroundColor = (rgb_color){255, 255, 240};
 	fLegendBackgroundColor = LowColor();
 		// the low color is restored by the BView unarchiving
-	fOffscreen = NULL;
 #ifdef __HAIKU__
 	fHistoryLayoutItem = NULL;
 	fLegendLayoutItem = NULL;
@@ -925,51 +923,6 @@ ActivityView::MinSize()
 #endif
 
 
-void
-ActivityView::FrameResized(float /*width*/, float /*height*/)
-{
-	_UpdateOffscreenBitmap();
-}
-
-
-void
-ActivityView::_UpdateOffscreenBitmap()
-{
-	BRect frame = _HistoryFrame();
-	frame.OffsetTo(B_ORIGIN);
-
-	if (fOffscreen != NULL && frame == fOffscreen->Bounds())
-		return;
-
-	delete fOffscreen;
-
-	// create offscreen bitmap
-
-	fOffscreen = new(std::nothrow) BBitmap(frame, B_BITMAP_ACCEPTS_VIEWS,
-		B_RGB32);
-	if (fOffscreen == NULL || fOffscreen->InitCheck() != B_OK) {
-		delete fOffscreen;
-		fOffscreen = NULL;
-		return;
-	}
-
-	BView* view = new BView(frame, NULL, B_FOLLOW_NONE, B_SUBPIXEL_PRECISE);
-	view->SetViewColor(fHistoryBackgroundColor);
-	view->SetLowColor(view->ViewColor());
-	fOffscreen->AddChild(view);
-}
-
-
-BView*
-ActivityView::_OffscreenView()
-{
-	if (fOffscreen == NULL)
-		return NULL;
-
-	return fOffscreen->ChildAt(0);
-}
-
-
 void
 ActivityView::MouseDown(BPoint where)
 {
@@ -1323,23 +1276,15 @@ ActivityView::_PositionForValue(DataSource* source, DataHistory* values,
 
 
 void
-ActivityView::_DrawHistory(bool drawBackground)
+ActivityView::_DrawHistory()
 {
-	_UpdateOffscreenBitmap();
-
 	BView* view = this;
-	if (fOffscreen != NULL) {
-		fOffscreen->Lock();
-		view = _OffscreenView();
-	}
 
 	BRect frame = _HistoryFrame();
 	BRect outerFrame = frame.InsetByCopy(-2, -2);
 
 	// draw the outer frame
-	uint32 flags = 0;
+	uint32 flags = BControlLook::B_BLEND_FRAME;
-	if (!drawBackground)
-		flags |= BControlLook::B_BLEND_FRAME;
 	be_control_look->DrawTextControlBorder(this, outerFrame,
 		outerFrame, fLegendBackgroundColor, flags);
 
@@ -1432,12 +1377,9 @@ ActivityView::_DrawHistory(bool drawBackground)
 		view->EndLineArray();
 	}
 
+	view->SetPenSize(1);
+
 	// TODO: add marks when an app started or quit
-	view->Sync();
-	if (fOffscreen != NULL) {
-		fOffscreen->Unlock();
-		DrawBitmap(fOffscreen, outerFrame.LeftTop());
-	}
 }
 
 
@@ -1467,11 +1409,7 @@ ActivityView::_UpdateResolution(int32 resolution, bool broadcast)
 void
 ActivityView::Draw(BRect updateRect)
 {
-	bool drawBackground = true;
+	_DrawHistory();
-	if (Parent() && (Parent()->Flags() & B_DRAW_ON_CHILDREN) != 0)
-		drawBackground = false;
-
-	_DrawHistory(drawBackground);
 
 	if (!fShowLegend)
 		return;
@@ -1481,12 +1419,6 @@ ActivityView::Draw(BRect updateRect)
 	if (LowUIColor() == B_NO_COLOR)
 		SetLowColor(fLegendBackgroundColor);
 
-	if (drawBackground) {
-		BRect backgroundFrame(legendFrame);
-		backgroundFrame.bottom += kDraggerSize;
-		FillRect(backgroundFrame, B_SOLID_LOW);
-	}
-
 	BAutolock _(fSourcesLock);
 
 	font_height fontHeight;
@@ -1520,9 +1452,6 @@ ActivityView::Draw(BRect updateRect)
 			label = source->ShortLabel();
 		TruncateString(&label, B_TRUNCATE_MIDDLE, possibleLabelWidth);
 
-		if (drawBackground)
-			SetHighColor(ui_color(B_PANEL_TEXT_COLOR));
-
 		if (be_control_look == NULL) {
 			DrawString(label.String(), BPoint(6 + colorBox.right, y));
 			DrawString(text.String(), BPoint(frame.right - width, y));

src/apps/activitymonitor/ActivityView.h

@@ -86,7 +86,6 @@ protected:
 	virtual	BSize		MinSize();
 #endif
 
-	virtual void		FrameResized(float width, float height);
 	virtual void		MouseDown(BPoint where);
 	virtual void		MouseUp(BPoint where);
 	virtual void		MouseMoved(BPoint where, uint32 transit,
@@ -101,8 +100,6 @@ private:
 			::Scale*	_ScaleFor(scale_type type);
 			void		_Refresh();
 	static	status_t	_RefreshThread(void* self);
-			void		_UpdateOffscreenBitmap();
-			BView*		_OffscreenView();
 			void		_UpdateFrame();
 			BRect		_HistoryFrame() const;
 			float		_LegendHeight() const;
@@ -111,7 +108,7 @@ private:
 			BRect		_LegendColorFrameAt(BRect frame, int32 index) const;
 			float		_PositionForValue(DataSource* source,
 							DataHistory* values, int64 value);
-			void		_DrawHistory(bool drawBackground);
+			void		_DrawHistory();
 			void		_UpdateResolution(int32 resolution,
 							bool broadcast = true);
 
@@ -124,7 +121,6 @@ private:
 
 	rgb_color			fHistoryBackgroundColor;
 	rgb_color			fLegendBackgroundColor;
-	BBitmap*			fOffscreen;
 #ifdef __HAIKU__
 	BLayoutItem*		fHistoryLayoutItem;
 	BLayoutItem*		fLegendLayoutItem;