Added class ListSelectionModel, representing a selection of list (i.e. indexed)

elements.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34567 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/debuganalyzer/gui/Jamfile

@@ -13,6 +13,7 @@ MergeObject DebugAnalyzer_gui.o
 	AbstractGeneralPage.cpp
 	ColorCheckBox.cpp
 	HeaderView.cpp
+	ListSelectionModel.cpp
 	SubWindow.cpp
 	SubWindowManager.cpp
 	:

src/apps/debuganalyzer/gui/ListSelectionModel.cpp

@@ -0,0 +1,224 @@
+/*
+ * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "ListSelectionModel.h"
+
+
+// #pragma mark - ListSelectionModel
+
+
+ListSelectionModel::ListSelectionModel()
+	:
+	fItemCount(0)
+{
+}
+
+
+ListSelectionModel::~ListSelectionModel()
+{
+}
+
+
+void
+ListSelectionModel::Clear()
+{
+	int32 selectedCount = fSelectedItems.Count();
+	if (selectedCount > 0) {
+		int32 firstSelected = fSelectedItems[0];
+		int32 lastSelected = fSelectedItems[selectedCount - 1];
+
+		fSelectedItems.Clear();
+
+		_NotifyItemsDeselected(firstSelected, lastSelected - firstSelected + 1);
+	}
+}
+
+
+bool
+ListSelectionModel::SelectItems(int32 itemIndex, int32 count,
+	bool extendSelection)
+{
+	int32 endItemIndex = itemIndex + count;
+
+	int32 index;
+	if (extendSelection) {
+		if (count <= 0)
+			return true;
+
+		index = _FindItem(itemIndex);
+
+		// count already selected items
+		int32 alreadySelectedCount = _CountSelectedItemsInRange(index,
+			endItemIndex);
+		if (alreadySelectedCount == count)
+			return true;
+
+		// make room for the new items
+		if (!fSelectedItems.InsertUninitialized(index + alreadySelectedCount,
+				count - alreadySelectedCount)) {
+			return false;
+		}
+	} else {
+		// TODO: Don't clear -- just resize to the right size!
+		Clear();
+		if (count <= 0)
+			return true;
+
+		index = 0;
+		if (!fSelectedItems.AddUninitialized(count))
+			return false;
+	}
+
+	for (int32 i = 0; i < count; i++)
+		fSelectedItems[index + i] = itemIndex + i;
+
+	_NotifyItemsSelected(itemIndex, count);
+
+	return true;
+}
+
+
+void
+ListSelectionModel::DeselectItems(int32 itemIndex, int32 count)
+{
+	int32 endItemIndex = itemIndex + count;
+	int32 index = _FindItem(itemIndex);
+
+	// count actually selected items
+	int32 actuallySelectedCount = _CountSelectedItemsInRange(index,
+		endItemIndex);
+	if (actuallySelectedCount == 0)
+		return;
+
+	fSelectedItems.Remove(index, actuallySelectedCount);
+
+	_NotifyItemsDeselected(itemIndex, count);
+}
+
+
+void
+ListSelectionModel::ItemsAdded(int32 itemIndex, int32 count)
+{
+	if (count <= 0)
+		return;
+
+	// re-index following items
+	int32 index = _FindItem(itemIndex);
+	int32 selectedCount = fSelectedItems.Count();
+	for (int32 i = index; i < selectedCount; i++)
+		fSelectedItems[i] += count;
+}
+
+
+void
+ListSelectionModel::ItemsRemoved(int32 itemIndex, int32 count)
+{
+	if (count <= 0)
+		return;
+
+	int32 index = _FindItem(itemIndex);
+
+	// count selected items in the range
+	int32 actuallySelectedCount = _CountSelectedItemsInRange(index,
+		itemIndex + count);
+	if (actuallySelectedCount > 0)
+		fSelectedItems.Remove(index, actuallySelectedCount);
+
+	// re-index following items
+	int32 selectedCount = fSelectedItems.Count();
+	for (int32 i = index; i < selectedCount; i++)
+		fSelectedItems[i] -= count;
+}
+
+
+bool
+ListSelectionModel::AddListener(Listener* listener)
+{
+	return fListeners.AddItem(listener);
+}
+
+
+void
+ListSelectionModel::RemoveListener(Listener* listener)
+{
+	fListeners.RemoveItem(listener);
+}
+
+
+int32
+ListSelectionModel::_FindItem(int32 itemIndex) const
+{
+	// binary search the index of the first item >= itemIndex
+	int32 lower = 0;
+	int32 upper = fSelectedItems.Count();
+
+	while (lower < upper) {
+		int32 mid = (lower + upper) / 2;
+
+		if (fSelectedItems[mid] < itemIndex)
+			lower = mid + 1;
+		else
+			upper = mid;
+	}
+
+	return lower;
+}
+
+
+int32
+ListSelectionModel::_CountSelectedItemsInRange(int32 index,
+	int32 endItemIndex) const
+{
+	int32 count = 0;
+	int32 selectedCount = fSelectedItems.Count();
+	for (int32 i = index; i < selectedCount; i++) {
+		if (SelectedItemAt(i) >= endItemIndex)
+			break;
+		count++;
+	}
+
+	return count;
+}
+
+
+void
+ListSelectionModel::_NotifyItemsSelected(int32 index, int32 count)
+{
+	int32 listenerCount = fListeners.CountItems();
+	for (int32 i = listenerCount - 1; i >= 0; i--)
+		fListeners.ItemAt(i)->ItemsSelected(this, index, count);
+}
+
+
+void
+ListSelectionModel::_NotifyItemsDeselected(int32 index, int32 count)
+{
+	int32 listenerCount = fListeners.CountItems();
+	for (int32 i = listenerCount - 1; i >= 0; i--)
+		fListeners.ItemAt(i)->ItemsDeselected(this, index, count);
+}
+
+
+// #pragma mark - Listener
+
+
+ListSelectionModel::Listener::~Listener()
+{
+}
+
+
+void
+ListSelectionModel::Listener::ItemsSelected(ListSelectionModel* model,
+	int32 index, int32 count)
+{
+}
+
+
+void
+ListSelectionModel::Listener::ItemsDeselected(ListSelectionModel* model,
+	int32 index, int32 count)
+{
+}

src/apps/debuganalyzer/gui/ListSelectionModel.h

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef LIST_SELECTION_MODEL_H
+#define LIST_SELECTION_MODEL_H
+
+
+#include <SupportDefs.h>
+
+#include <ObjectList.h>
+
+#include "../debugger/util/Array.h"
+
+
+class ListSelectionModel {
+public:
+			class Listener;
+
+public:
+								ListSelectionModel();
+								~ListSelectionModel();
+
+			int32				CountSelectedItems() const
+									{ return fSelectedItems.Count(); }
+			int32				SelectedItemAt(int32 index) const;
+			bool				IsItemSelected(int32 itemIndex) const;
+
+			void				Clear();
+			bool				SelectItem(int32 itemIndex,
+									bool extendSelection);
+			bool				SelectItems(int32 itemIndex, int32 count,
+									bool extendSelection);
+			void				DeselectItem(int32 itemIndex);
+			void				DeselectItems(int32 itemIndex, int32 count);
+
+			void				ItemsAdded(int32 itemIndex, int32 count);
+			void				ItemsRemoved(int32 itemIndex, int32 count);
+
+			bool				AddListener(Listener* listener);
+			void				RemoveListener(Listener* listener);
+
+private:
+			typedef BObjectList<Listener> ListenerList;
+
+private:
+			int32				_FindItem(int32 itemIndex) const;
+			int32				_CountSelectedItemsInRange(int32 index,
+									int32 endItemIndex) const;
+
+			void				_NotifyItemsSelected(int32 index, int32 count);
+			void				_NotifyItemsDeselected(int32 index,
+									int32 count);
+
+private:
+			int32				fItemCount;
+			Array<int32>		fSelectedItems;
+			ListenerList		fListeners;
+};
+
+
+class ListSelectionModel::Listener {
+public:
+	virtual						~Listener();
+
+	virtual	void				ItemsSelected(ListSelectionModel* model,
+									int32 index, int32 count);
+	virtual	void				ItemsDeselected(ListSelectionModel* model,
+									int32 index, int32 count);
+};
+
+
+inline bool
+ListSelectionModel::IsItemSelected(int32 itemIndex) const
+{
+	int32 index = _FindItem(itemIndex);
+	return index < fSelectedItems.Count() && fSelectedItems[index] == itemIndex;
+}
+
+
+inline int32
+ListSelectionModel::SelectedItemAt(int32 index) const
+{
+	return index >= 0 && index < fSelectedItems.Count()
+		? fSelectedItems[index] : -1;
+}
+
+
+inline bool
+ListSelectionModel::SelectItem(int32 itemIndex, bool extendSelection)
+{
+	return SelectItems(itemIndex, 1, extendSelection);
+}
+
+
+inline void
+ListSelectionModel::DeselectItem(int32 itemIndex)
+{
+	DeselectItems(itemIndex, 1);
+}
+
+
+#endif	// LIST_SELECTION_MODEL_H