From 4e0c2a797d01708bc3c1a49f2d496dc465f833cf Mon Sep 17 00:00:00 2001
From: Stefano Ceccherini <stefano.ceccherini@gmail.com>
Date: Fri, 3 Oct 2008 06:03:27 +0000
Subject: [PATCH] Menus can be scrolled also using the mouse wheel

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27844 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 headers/private/interface/MenuWindow.h |  8 +++--
 src/kits/interface/Menu.cpp            | 25 ++++++++++++++-
 src/kits/interface/MenuWindow.cpp      | 43 ++++++++++++++++++++------
 3 files changed, 62 insertions(+), 14 deletions(-)

diff --git a/headers/private/interface/MenuWindow.h b/headers/private/interface/MenuWindow.h
index 5d5a8039be..1f8053ab60 100644
--- a/headers/private/interface/MenuWindow.h
+++ b/headers/private/interface/MenuWindow.h
@@ -34,8 +34,9 @@ class BMenuWindow : public BWindow {
 		void AttachScrollers();
 		void DetachScrollers();
 
-		bool CheckForScrolling(BPoint cursor);
-
+		bool CheckForScrolling(const BPoint &cursor);
+		bool TryScrollBy(const float &step);
+	
 	private:
 		BMenu *fMenu;
 		BMenuFrame *fMenuFrame;
@@ -45,7 +46,8 @@ class BMenuWindow : public BWindow {
 		float fValue;
 		float fLimit;
 		
-		bool _Scroll(BPoint cursor);
+		bool _Scroll(const BPoint &cursor);
+		void _ScrollBy(const float &step);
 };
 
 }	// namespace BPrivate
diff --git a/src/kits/interface/Menu.cpp b/src/kits/interface/Menu.cpp
index 87198bda37..dfd0376e5b 100644
--- a/src/kits/interface/Menu.cpp
+++ b/src/kits/interface/Menu.cpp
@@ -813,7 +813,30 @@ BMenu::Superitem() const
 void
 BMenu::MessageReceived(BMessage *msg)
 {
-	BView::MessageReceived(msg);
+	switch (msg->what) {
+		case B_MOUSE_WHEEL_CHANGED:
+		{
+			//float deltaX = 0
+			float deltaY = 0;
+			//msg->FindFloat("be:wheel_delta_x", &deltaX);
+			msg->FindFloat("be:wheel_delta_y", &deltaY);
+			if (deltaY == 0)
+				return;
+			
+			BMenuWindow *window = dynamic_cast<BMenuWindow *>(Window());
+			if (window == NULL)
+				return;
+				
+			window->TryScrollBy(deltaY);	
+			
+			break;
+		}
+		default:
+			BView::MessageReceived(msg);
+			break;
+	}
+	
+	
 }
 
 
diff --git a/src/kits/interface/MenuWindow.cpp b/src/kits/interface/MenuWindow.cpp
index ba5a7e548d..64463cd235 100644
--- a/src/kits/interface/MenuWindow.cpp
+++ b/src/kits/interface/MenuWindow.cpp
@@ -336,7 +336,7 @@ BMenuWindow::DetachScrollers()
 
 
 bool
-BMenuWindow::CheckForScrolling(BPoint cursor)
+BMenuWindow::CheckForScrolling(const BPoint &cursor)
 {
 	if (!fMenuFrame || !fUpperScroller || !fLowerScroller)
 		return false;
@@ -346,17 +346,45 @@ BMenuWindow::CheckForScrolling(BPoint cursor)
 
 
 bool
-BMenuWindow::_Scroll(BPoint cursor)
+BMenuWindow::TryScrollBy(const float &step)
+{
+	if (!fMenuFrame || !fUpperScroller || !fLowerScroller)
+		return false;
+	
+	_ScrollBy(step);
+	
+	return true;
+}
+
+
+bool
+BMenuWindow::_Scroll(const BPoint &where)
 {
 	ASSERT((fLowerScroller != NULL));
 	ASSERT((fUpperScroller != NULL));
 	
-	ConvertFromScreen(&cursor);
+	const BPoint cursor = ConvertFromScreen(where);
 
 	BRect lowerFrame = fLowerScroller->Frame();
 	BRect upperFrame = fUpperScroller->Frame();
 
 	if (fLowerScroller->IsEnabled() && lowerFrame.Contains(cursor)) {		
+		_ScrollBy(1);
+	} else if (fUpperScroller->IsEnabled() && upperFrame.Contains(cursor)) {		
+		_ScrollBy(-1);
+	} else
+		return false;
+
+	snooze(10000);
+
+	return true;
+}
+
+
+void
+BMenuWindow::_ScrollBy(const float &step)
+{
+	if (step > 0) {
 		if (fValue == 0) {
 			fUpperScroller->SetEnabled(true);
 			fUpperScroller->Invalidate();
@@ -374,7 +402,7 @@ BMenuWindow::_Scroll(BPoint cursor)
 			fMenu->ScrollBy(0, kScrollStep);
 			fValue += kScrollStep;
 		}
-	} else if (fUpperScroller->IsEnabled() && upperFrame.Contains(cursor)) {		
+	} else if (step < 0) {
 		if (fValue == fLimit) {
 			fLowerScroller->SetEnabled(true);
 			fLowerScroller->Invalidate();
@@ -390,11 +418,6 @@ BMenuWindow::_Scroll(BPoint cursor)
 			fMenu->ScrollBy(0, -kScrollStep);
 			fValue -= kScrollStep;
 		}
-	} else
-		return false;
-
-	snooze(10000);
-
-	return true;
+	}
 }