* Added layout-friendly constructors and implemented Min/Max/PreferredSize(),

and DoLayout(). When the B_SUPPORTS_LAYOUT view flag is set (as is by
  default when using one of the new constructors) the BBox completely manages
  one true child (the first child that is not the label view).
* Centralized the layout related computation in new method
  _ValidateLayoutData(). The computed infos are cached in a new private
  LayoutData structure.
* GetPreferredSize() was broken in several respects. It does now return the
  same result as PreferredSize(). If B_SUPPORTS_LAYOUT is not set, these are
  the sums of the insets induces by the frame and the label. I.e. those values
  can for instance be added to the child's preferred size to compute the
  preferred size of the compound.

Not sure, if the Haiku-only TopBorderOffset() and InnerFrame() functions still
make sense. With layout management they're actually superfluous.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21356 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/Box.h

@@ -12,10 +12,17 @@
 class BBox : public BView {
 	public:
 							BBox(BRect frame, const char *name = NULL,
-								uint32 resizingMode = B_FOLLOW_LEFT | B_FOLLOW_TOP,
+								uint32 resizingMode = B_FOLLOW_LEFT
+									| B_FOLLOW_TOP,
 								uint32 flags = B_WILL_DRAW | B_FRAME_EVENTS
 									| B_NAVIGABLE_JUMP,
 								border_style border = B_FANCY_BORDER);
+							BBox(const char* name,
+								uint32 flags = B_WILL_DRAW | B_FRAME_EVENTS
+									| B_NAVIGABLE_JUMP,
+								border_style border = B_FANCY_BORDER,
+								BView* child = NULL);
+							BBox(border_style border, BView* child);
 		virtual				~BBox();
 
 		/* Archiving */
@@ -60,7 +67,16 @@ class BBox : public BView {
 
 		virtual status_t	Perform(perform_code d, void* arg);
 
+		virtual	BSize		MinSize();
+		virtual	BSize		MaxSize();
+		virtual	BSize		PreferredSize();
+
+		virtual	void		InvalidateLayout(bool descendants = false);
+		virtual	void		DoLayout();
+
 	private:
+		struct LayoutData;
+
 		virtual	void		_ReservedBox1();
 		virtual	void		_ReservedBox2();
 
@@ -71,11 +87,14 @@ class BBox : public BView {
 		void				_DrawFancy(BRect labelBox);
 		void				_ClearLabel();
 
+		BView*				_Child() const;
+		void				_ValidateLayoutData();
+
 		char*				fLabel;
 		BRect				fBounds;
 		border_style		fStyle;
 		BView*				fLabelView;
-		BRect*				fLabelBox;
+		LayoutData*			fLayoutData;
 };
 
 #endif	// _BOX_H