Implemented BSize returning layout methods.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27406 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/ScrollBar.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001-2006, Haiku, Inc.
+ * Copyright (c) 2001-2008, Haiku, Inc. All rights reserved.
  * Distributed under the terms of the MIT license.
  *
  * Authors:
@@ -71,6 +71,10 @@ class BScrollBar : public BView {
 		virtual void		AllDetached();
 		virtual status_t	GetSupportedSuites(BMessage *data);
 
+		virtual	BSize		MinSize();
+		virtual	BSize		MaxSize();
+		virtual	BSize		PreferredSize();
+
 		virtual status_t	Perform(perform_code d, void *arg);
 
 #if DISABLES_ON_WINDOW_DEACTIVATION
@@ -106,6 +110,8 @@ class BScrollBar : public BView {
 								const BRect& updateRect,
 								bool enabled, bool down);
 
+				BSize		_MinSize() const;
+
 				float		fMin;
 				float		fMax;
 				float		fSmallStep;

src/kits/interface/ScrollBar.cpp

@@ -12,6 +12,7 @@
 
 #include <ScrollBar.h>
 
+#include <LayoutUtils.h>
 #include <Message.h>
 #include <OS.h>
 #include <Shape.h>
@@ -1083,6 +1084,37 @@ BScrollBar::GetSupportedSuites(BMessage *message)
 }
 
 
+BSize
+BScrollBar::MinSize()
+{
+	return BLayoutUtils::ComposeSize(ExplicitMinSize(), _MinSize());
+}
+
+
+BSize
+BScrollBar::MaxSize()
+{
+	BSize maxSize = _MinSize();
+	if (fOrientation == B_HORIZONTAL)	
+		maxSize.width = B_SIZE_UNLIMITED;
+	else
+		maxSize.height = B_SIZE_UNLIMITED;
+	return BLayoutUtils::ComposeSize(ExplicitMaxSize(), maxSize);
+}
+
+
+BSize
+BScrollBar::PreferredSize()
+{
+	BSize preferredSize = _MinSize();
+	if (fOrientation == B_HORIZONTAL)	
+		preferredSize.width = 2 * preferredSize.width;
+	else
+		preferredSize.height = 2 * preferredSize.height;
+	return BLayoutUtils::ComposeSize(ExplicitPreferredSize(), preferredSize);
+}
+
+
 status_t
 BScrollBar::Perform(perform_code d, void* arg)
 {
@@ -1643,3 +1675,20 @@ BScrollBar::_DrawArrowButton(int32 direction, bool doubleArrows, BRect r,
 	EndLineArray();
 }
 
+
+BSize
+BScrollBar::_MinSize() const
+{
+	BSize minSize;
+	if (fOrientation == B_HORIZONTAL) {
+		minSize.width = 2 * B_V_SCROLL_BAR_WIDTH
+			+ 2 * fPrivateData->fScrollBarInfo.min_knob_size;
+		minSize.height = B_H_SCROLL_BAR_HEIGHT;
+	} else {
+		minSize.width = B_V_SCROLL_BAR_WIDTH;
+		minSize.height = 2 * B_H_SCROLL_BAR_HEIGHT
+			+ 2 * fPrivateData->fScrollBarInfo.min_knob_size;
+	}
+	return minSize;
+}
+