First try at menu scrolling, courthesy of Łukasz Zemczak. Works more or less, although a bit buggy

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19343 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/interface/MenuWindow.h

@@ -30,7 +30,44 @@
 #include <Window.h>
 
 class BMenu;
-class BMenuScroller;
+class BMenuScroller : public BView {
+	public:
+		BMenuScroller(BRect frame, BMenu *menu);
+		virtual ~BMenuScroller();
+
+		virtual void Pulse();
+		virtual void Draw(BRect updateRect);
+
+	private:
+		BMenu *fMenu;
+		BRect fUpperButton;
+		BRect fLowerButton;
+
+		float fValue;
+		float fLimit;
+
+		bool fUpperEnabled;
+		bool fLowerEnabled;
+
+		uint32 fButton;
+		BPoint fPosition;
+};
+
+
+class BMenuFrame : public BView {
+	public:
+		BMenuFrame(BMenu *menu);
+
+		virtual void AttachedToWindow();
+		virtual void DetachedFromWindow();
+		virtual void Draw(BRect updateRect);
+
+  private:
+		friend class BMenuWindow;
+
+		BMenu *fMenu;
+};
+
 
 class BMenuWindow : public BWindow {
 	public:
@@ -40,11 +77,12 @@ public:
 		void AttachMenu(BMenu *menu);
 		void DetachMenu();
 	
-	void UpdateScrollers();
+		void AttachScrollers();
+		void DetachScrollers();
 
 	private:
-	BMenuScroller *fUpperScroller;
-	BMenuScroller *fLowerScroller;
+		BMenuScroller *fScroller;
+		BMenuFrame *fMenuFrame;
 };
 
 #endif

src/kits/interface/Menu.cpp

@@ -1184,6 +1184,7 @@ BMenu::_show(bool selectFirstItem)
 	if (window->Lock()) {
 		fAttachAborted = false;
 		window->AttachMenu(this);
+		fCachedMenuWindow = window;
 
 		// Menu didn't have the time to add its items: aborting...
 		if (fAttachAborted) {
@@ -1203,6 +1204,7 @@ BMenu::_show(bool selectFirstItem)
 			MoveTo(1, 1);
 	
 		UpdateWindowViewSize();
+		fCachedMenuWindow = NULL;
 		window->Show();
 		
 		if (selectFirstItem)
@@ -2061,13 +2063,27 @@ BMenu::UpdateWindowViewSize(bool upWind)
 	BRect frame = CalcFrame(ScreenLocation(), &scroll);
 	ResizeTo(frame.Width(), frame.Height());
 
-	if (fItems.CountItems() > 0)
+	if (fItems.CountItems() > 0) {
+		if (!scroll) {
 			window->ResizeTo(Bounds().Width() + 2, Bounds().Height() + 2);
-	else {
+		} else {
+			BScreen screen(window);
+
+			// If we need scrolling, resize the window to fit the screen and
+			// attach scrollers to our cached MenuWindow.
+			window->ResizeTo(Bounds().Width() + 2, screen.Frame().bottom - 10);
+			
+			if (fCachedMenuWindow)
+				fCachedMenuWindow->AttachScrollers();
+
+			frame.top = 0;
+		}
+	} else {
 		CacheFontInfo();
 		window->ResizeTo(StringWidth(kEmptyMenuLabel) + fPad.left + fPad.right,
 						fFontHeight + fPad.top + fPad.bottom);
 	}
+	
 	window->MoveTo(frame.LeftTop());
 }
 

src/kits/interface/MenuWindow.cpp

@@ -5,12 +5,11 @@
  * Authors:
  *		Marc Flerackers (mflerackers@androme.be)
  *		Stefano Ceccherini (burton666@libero.it)
+ *		
  */
 
 //!	BMenuWindow is a custom BWindow for BMenus.
 
-// TODO: Add scrollers
-
 #include <Menu.h>
 
 #include <MenuPrivate.h>
@@ -18,27 +17,133 @@
 #include <WindowPrivate.h>
 
 
-// This draws the frame around the BMenu
-class BMenuFrame : public BView {
-	public:
-		BMenuFrame(BMenu *menu);
+const int kScrollerHeight = 10;
+const int kScrollStep = 16;
 
-		virtual void AttachedToWindow();
-		virtual void DetachedFromWindow();
-		virtual void Draw(BRect updateRect);
+BMenuScroller::BMenuScroller(BRect frame, BMenu *menu)
+	:	BView(frame, "menu scroller", 0, B_WILL_DRAW | B_FRAME_EVENTS 
+			| B_PULSE_NEEDED),
+	fMenu(menu),
+	fUpperButton(0, 0, frame.right, kScrollerHeight),
+	fLowerButton(0, frame.bottom - kScrollerHeight, frame.right, frame.bottom),
+	fValue(0),
+	fUpperEnabled(false),
+	fLowerEnabled(true)
+{
+	if (!menu)
+		debugger("BMenuScroller(): Scroller not attached to a menu!");
+	SetViewColor(ui_color(B_MENU_BACKGROUND_COLOR));
 
-	private:
-		BMenu *fMenu;
-};
+	fLimit = menu->Bounds().Height() - (frame.Height() - 2 * kScrollerHeight);
+}
+
+
+BMenuScroller::~BMenuScroller()
+{
+}
+
+
+void
+BMenuScroller::Pulse()
+{
+	// To reduce the overhead even a little, fButton and fPosition were
+	// made private variables.
+
+	// We track the mouse and move the scrollers depending on its position.
+	GetMouse(&fPosition, &fButton);
+	if (fLowerButton.Contains(fPosition) && fLowerEnabled) {
+		if (fValue == 0) {
+			fUpperEnabled = true;
+			
+			Invalidate(fUpperButton);
+		}
+
+		if (fValue + kScrollStep >= fLimit) {
+			// If we reached the limit, we don't want to scroll a whole
+			// 'step' if not needed.
+			fMenu->ScrollBy(0, fLimit - fValue);
+			fValue = fLimit;
+			fLowerEnabled = false;
+			Invalidate(fLowerButton);
+		} else {
+			fMenu->ScrollBy(0, kScrollStep);
+			fValue += kScrollStep;
+		}
+	} else if (fUpperButton.Contains(fPosition) && fUpperEnabled) {
+		if (fValue == fLimit) {
+			fLowerEnabled = true;
+			Invalidate(fLowerButton);
+		}
+
+		if (fValue - kScrollStep <= 0) {
+			fMenu->ScrollBy(0, -fValue);
+			fValue = 0;
+			fUpperEnabled = false;
+			Invalidate(fUpperButton);
+		} else {
+			fMenu->ScrollBy(0, -kScrollStep);
+			fValue -= kScrollStep;
+		}
+
+		// In this case, we need to redraw the lower button because of a
+		// probable bug in ScrollBy handling. The scrolled view is drawing below 
+		// its bounds, dirtying our button in this process.
+		// Redrawing it everytime makes scrolling a little slower.
+		// TODO: Try to find why and fix this.
+		Draw(fLowerButton);
+	}
+}
+
+
+void
+BMenuScroller::Draw(BRect updateRect)
+{
+	SetLowColor(tint_color(ui_color(B_MENU_BACKGROUND_COLOR), B_DARKEN_1_TINT));
+	float middle = Bounds().right / 2;
+
+	// Draw the upper arrow.
+	if (updateRect.Intersects(fUpperButton)) {
+		if (fUpperEnabled)
+			SetHighColor(0, 0, 0);
+		else
+			SetHighColor(tint_color(ui_color(B_MENU_BACKGROUND_COLOR), 
+						B_DARKEN_2_TINT));
+
+		FillRect(fUpperButton, B_SOLID_LOW);
+	
+		FillTriangle(BPoint(middle, (kScrollerHeight / 2) - 3),
+				BPoint(middle + 5, (kScrollerHeight / 2) + 2),
+				BPoint(middle - 5, (kScrollerHeight / 2) + 2));
+	}
+
+	// Draw the lower arrow.
+	if (updateRect.Intersects(fLowerButton)) {
+		if (fLowerEnabled)
+			SetHighColor(0, 0, 0);
+		else
+			SetHighColor(tint_color(ui_color(B_MENU_BACKGROUND_COLOR), 
+						B_DARKEN_2_TINT));
+
+		FillRect(fLowerButton, B_SOLID_LOW);
+
+		FillTriangle(BPoint(middle, fLowerButton.bottom - (kScrollerHeight / 2) + 3),
+				BPoint(middle + 5, fLowerButton.bottom - (kScrollerHeight / 2) - 2),
+				BPoint(middle - 5, fLowerButton.bottom - (kScrollerHeight / 2) - 2));
+	}
+}
+
+
+//	#pragma mark -
 
 
 BMenuWindow::BMenuWindow(const char *name)
 	// The window will be resized by BMenu, so just pass a dummy rect
 	: BWindow(BRect(0, 0, 0, 0), name, B_BORDERED_WINDOW_LOOK, kMenuWindowFeel,
 			B_NOT_ZOOMABLE | B_AVOID_FOCUS),
-	fUpperScroller(NULL),
-	fLowerScroller(NULL)
+	fScroller(NULL),
+	fMenuFrame(NULL)
 {
+	SetPulseRate(200000);
 }
 
 
@@ -50,11 +155,11 @@ BMenuWindow::~BMenuWindow()
 void
 BMenuWindow::AttachMenu(BMenu *menu)
 {
-	if (CountChildren() > 0)
-		debugger("BMenuWindow (%s): a menu is already attached!");
+	if (fMenuFrame)
+		debugger("BMenuWindow: a menu is already attached!");
 	if (menu != NULL) {
-		BMenuFrame *menuFrame = new BMenuFrame(menu);
-		AddChild(menuFrame);
+		fMenuFrame = new BMenuFrame(menu);
+		AddChild(fMenuFrame);
 		menu->MakeFocus(true);
 	}
 }
@@ -63,8 +168,53 @@ BMenuWindow::AttachMenu(BMenu *menu)
 void
 BMenuWindow::DetachMenu()
 {
-	if (CountChildren() > 0)
-		RemoveChild(ChildAt(0));	
+	if (fMenuFrame) {
+		if (fScroller) {
+			DetachScrollers();
+		} else {
+			RemoveChild(fMenuFrame);
+		}
+		delete fMenuFrame;
+		fMenuFrame = NULL;
+	}
+}
+
+
+void
+BMenuWindow::AttachScrollers()
+{
+	// We want to attach a scroller only if there's a menu frame already
+	// existing.
+	if (fScroller || !fMenuFrame)
+		return;
+
+	RemoveChild(fMenuFrame);
+	fScroller = new BMenuScroller(Bounds(), fMenuFrame->fMenu);
+	fScroller->AddChild(fMenuFrame);
+	AddChild(fScroller);
+
+	fMenuFrame->fMenu->MakeFocus(true);
+
+	fMenuFrame->ResizeBy(0, -2 * kScrollerHeight);
+	fMenuFrame->MoveBy(0, kScrollerHeight);
+}
+
+
+void
+BMenuWindow::DetachScrollers()
+{
+	if(!fScroller || !fMenuFrame)
+		return;
+
+	// BeOS doesn't remember the position where the last scrolling ended,
+	// so we just scroll back to the beginning.
+	fMenuFrame->fMenu->ScrollTo(0, 0);
+
+	fScroller->RemoveChild(fMenuFrame);
+	RemoveChild(fScroller);
+
+	delete fScroller;
+	fScroller = NULL;
 }