BLayoutUtils: Add GetLayoutTreeDump()

Returns a debug output string listing the basic layout properties of
the view/item hierarchy.

headers/os/interface/LayoutUtils.h

@@ -1,16 +1,21 @@
 /*
- * Copyright 2006, Haiku, Inc. All rights reserved.
+ * Copyright 2006-2013, Haiku, Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef	_LAYOUT_UTILS_H
 #define	_LAYOUT_UTILS_H
 
+
 #include <Alignment.h>
 #include <Rect.h>
 #include <Size.h>
+#include <String.h>
 
+
+class BLayoutItem;
 class BView;
 
+
 class BLayoutUtils {
 public:
 //	static	float				AddSizesFloat(float a, float b);
@@ -36,6 +41,17 @@ public:
 									BAlignment alignment);
 	static	void				AlignInFrame(BView* view, BRect frame);
 	static	BRect				MoveIntoFrame(BRect rect, BSize frameSize);
+
+	// debugging
+	static	BString				GetLayoutTreeDump(BView* view);
+	static	BString				GetLayoutTreeDump(BLayoutItem* item);
+
+private:
+	static	void				_GetLayoutTreeDump(BView* view, int level,
+									BString& _output);
+	static	void				_GetLayoutTreeDump(BLayoutItem* item,
+									int level, bool isViewLayout,
+									BString& _output);
 };
 
 #endif	//	_LAYOUT_UTILS_H

src/kits/interface/LayoutUtils.cpp

@@ -1,12 +1,17 @@
 /*
- * Copyright 2006-2010, Ingo Weinhold, [email protected].
+ * Copyright 2006-2013, Ingo Weinhold, [email protected].
  * Distributed under the terms of the MIT License.
  */
 
 #include <LayoutUtils.h>
 
+#include <typeinfo>
+
+#include <Layout.h>
 #include <View.h>
 
+#include "ViewLayoutItem.h"
+
 
 // // AddSizesFloat
 // float
@@ -230,3 +235,111 @@ BLayoutUtils::MoveIntoFrame(BRect rect, BSize frameSize)
 
 	return rect.OffsetToSelf(leftTop);
 }
+
+
+/*static*/ BString
+BLayoutUtils::GetLayoutTreeDump(BView* view)
+{
+	BString result;
+	_GetLayoutTreeDump(view, 0, result);
+	return result;
+}
+
+
+/*static*/ BString
+BLayoutUtils::GetLayoutTreeDump(BLayoutItem* item)
+{
+	BString result;
+	_GetLayoutTreeDump(item, 0, false, result);
+	return result;
+}
+
+
+/*static*/ void
+BLayoutUtils::_GetLayoutTreeDump(BView* view, int level, BString& _output)
+{
+	BString indent;
+	indent.SetTo(' ', level * 2);
+
+	if (view == NULL) {
+		_output << indent << "<null view>\n";
+		return;
+	}
+
+	BRect frame = view->Frame();
+	BSize min = view->MinSize();
+	BSize max = view->MinSize();
+	BSize preferred = view->PreferredSize();
+	_output << BString().SetToFormat(
+		"%sview %p (%s):\n"
+		"%s  frame: (%f, %f, %f, %f)\n"
+		"%s  min:   (%f, %f)\n"
+		"%s  max:   (%f, %f)\n"
+		"%s  pref:  (%f, %f)\n",
+		indent.String(), view, typeid(*view).name(),
+		indent.String(), frame.left, frame.top, frame.right, frame.bottom,
+		indent.String(), min.width, min.height,
+		indent.String(), max.width, max.height,
+		indent.String(), preferred.width, preferred.height);
+
+	if (BLayout* layout = view->GetLayout()) {
+		_GetLayoutTreeDump(layout, level, true, _output);
+		return;
+	}
+
+	int32 count = view->CountChildren();
+	for (int32 i = 0; i < count; i++) {
+		_output << indent << "  ---\n";
+		_GetLayoutTreeDump(view->ChildAt(i), level + 1, _output);
+	}
+}
+
+
+/*static*/ void
+BLayoutUtils::_GetLayoutTreeDump(BLayoutItem* item, int level,
+	bool isViewLayout, BString& _output)
+{
+	if (BViewLayoutItem* viewItem = dynamic_cast<BViewLayoutItem*>(item)) {
+		_GetLayoutTreeDump(viewItem->View(), level, _output);
+		return;
+	}
+
+	BString indent;
+	indent.SetTo(' ', level * 2);
+
+	if (item == NULL) {
+		_output << indent << "<null item>\n";
+		return;
+	}
+
+	BLayout* layout = dynamic_cast<BLayout*>(item);
+	BRect frame = item->Frame();
+	BSize min = item->MinSize();
+	BSize max = item->MinSize();
+	BSize preferred = item->PreferredSize();
+	if (isViewLayout) {
+		_output << indent << BString().SetToFormat("  [layout %p (%s)]\n",
+			layout, typeid(*layout).name());
+	} else {
+		_output << indent << BString().SetToFormat("item %p (%s):\n",
+			item, typeid(*item).name());
+	}
+	_output << BString().SetToFormat(
+		"%s  frame: (%f, %f, %f, %f)\n"
+		"%s  min:   (%f, %f)\n"
+		"%s  max:   (%f, %f)\n"
+		"%s  pref:  (%f, %f)\n",
+		indent.String(), frame.left, frame.top, frame.right, frame.bottom,
+		indent.String(), min.width, min.height,
+		indent.String(), max.width, max.height,
+		indent.String(), preferred.width, preferred.height);
+
+	if (layout == NULL)
+		return;
+
+	int32 count = layout->CountItems();
+	for (int32 i = 0; i < count; i++) {
+		_output << indent << "  ---\n";
+		_GetLayoutTreeDump(layout->ItemAt(i), level + 1, false, _output);
+	}
+}