Not in mood for too much coding, I had a look through the code tonight. And guess what? Like Stefano

the other day, I discovered, not a bug, but how to invalidate only the area that requires it when
changing window order (selecting or moving to back a window). Stuppid me, that stuff didn't worked
because I forgot how windows were arranged in the list returned by Workspace::GetWMState(). I was
iterating the wrong way! :-)



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14839 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/RootLayer.cpp

@@ -302,27 +302,27 @@ RootLayer::ResizeBy(float x, float y)
 Layer*
 RootLayer::FirstChild() const
 {
-	fWinBorderIndex = fWMState.WindowList.CountItems()-1;
+	fWinBorderIndex = 0;
-	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex--));
+	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex++));
 }
 
 Layer*
 RootLayer::NextChild() const
 {
-	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex--));
+	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex++));
 }
 
 Layer*
 RootLayer::PreviousChild() const
 {
-	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex++));
+	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex--));
 }
 
 Layer*
 RootLayer::LastChild() const
 {
-	fWinBorderIndex = 0;
+	fWinBorderIndex = fWMState.WindowList.CountItems()-1;
-	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex++));
+	return static_cast<Layer*>(fWMState.WindowList.ItemAt(fWinBorderIndex--));
 }
 
 
@@ -836,6 +836,7 @@ RootLayer::RevealNewWMState(Workspace::State &oldWMState)
 			}
 		}
 
+		// for new windows, invalidate(rebuild & redraw) the maximum that it can occupy.
 		for (int32 i = 0; i < newWindowCount; ++i) {
 			Layer *layer = static_cast<Layer*>(fWMState.WindowList.ItemAtFast(i));
 			if (!layer)
@@ -849,6 +850,8 @@ RootLayer::RevealNewWMState(Workspace::State &oldWMState)
 				}
 			if (isNewWindow) {
 				BRegion invalid;
+
+				// invalidate the maximum area which this layer/window can occupy.
 				layer->GetWantedRegion(invalid);
 
 				MarkForRebuild(invalid);
@@ -859,6 +862,7 @@ RootLayer::RevealNewWMState(Workspace::State &oldWMState)
 			}
 		}
 
+		// if a window came in front ot others, invalidate its previously hidden area.
 		oldWindowCount = oldStrippedList.CountItems();
 		newWindowCount = newStrippedList.CountItems();
 		for (int32 i = 0; i < oldWindowCount; ++i) {
@@ -867,11 +871,12 @@ RootLayer::RevealNewWMState(Workspace::State &oldWMState)
 				continue;
 			if (i < newStrippedList.IndexOf(layer)) {
 				BRegion invalid;
+
+				// start by invalidating the maximum area which this layer/window can occupy.
 				layer->GetWantedRegion(invalid);
 
-// TODO: we need to invalidate only the ares that became visible
+				// no reason to invalidate what's currently visible.
-//		 not the whole surface of this layer!
+				invalid.Exclude(&layer->FullVisible());
-//				invalid.Exclude(&layer->FullVisible());
 
 				MarkForRebuild(invalid);
 				MarkForRedraw(invalid);

src/servers/app/Workspace.cpp

@@ -227,6 +227,15 @@ Workspace::Active() const
 	return NULL;
 }
 
+/*!
+	\brief Method that returns the state of window manager.
+	\param state - a pointer to a valid Workspace::State structure
+	\return void
+
+	Fills the state structure with the most important window manager attibutes:
+front window, focus window, active window and the list of windows starting from
+the backmost one at position 0 and ending with the most visible window.
+*/
 void
 Workspace::GetState(Workspace::State *state) const
 {
@@ -234,11 +243,11 @@ Workspace::GetState(Workspace::State *state) const
 	state->Focus = Focus();
 	state->Active = Active();
 
-	ListData *cursor = fBottomItem;
+	ListData *cursor = fTopItem;
 	while (cursor) {
 		if (!cursor->layerPtr->IsHidden())
 			state->WindowList.AddItem(cursor->layerPtr);
-		cursor = cursor->upperItem;
+		cursor = cursor->lowerItem;
 	}
 }
 bool