Added initial implementation of Undo for OBOS ShowImage! Now, users can Undo/Redo merge/paste operations. Still need to enhance Undo further so that other operations can be undone, also need to account for image rotations and similar operations.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@5693 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/showimage/Jamfile

@@ -6,6 +6,7 @@ App ShowImage : ShowImageApp.cpp
 	ShowImageConstants.cpp
 	ShowImageSettings.cpp
 	ShowImageStatusView.cpp
+	ShowImageUndo.cpp
 	ShowImageView.cpp
 	ShowImageWindow.cpp
 	PrintOptionsWindow.cpp

src/apps/showimage/ShowImageConstants.h

@@ -44,6 +44,7 @@ const uint32 MSG_CLIPBOARD_CHANGED	= 'mCLP';
 const uint32 MSG_DITHER_IMAGE		= 'mDIM';
 const uint32 MSG_MODIFIED			= 'mMOD';
 const uint32 MSG_UPDATE_STATUS		= 'mUPS';
+const uint32 MSG_UNDO_STATE			= 'mUNS';
 const uint32 MSG_SELECTION			= 'mSEL';
 const uint32 MSG_SELECTION_BITMAP	= 'mSBT';
 const uint32 MSG_PAGE_FIRST			= 'mPGF';

src/apps/showimage/ShowImageUndo.cpp

@@ -0,0 +1,98 @@
+/*****************************************************************************/
+// ShowImageUndo
+// Written by Michael Wilber
+//
+// ShowImageUndo.cpp
+//
+//
+// Copyright (c) 2003 OpenBeOS Project
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+// and/or sell copies of the Software, and to permit persons to whom the 
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included 
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+/*****************************************************************************/
+
+#include "ShowImageUndo.h"
+
+ShowImageUndo::ShowImageUndo()
+{
+	fWindow = NULL;
+	fUndoType = 0;
+	fRestore = NULL;
+	fSelection = NULL;
+}
+
+ShowImageUndo::~ShowImageUndo()
+{
+	InternalClear();
+}
+
+void
+ShowImageUndo::InternalClear()
+{
+	fUndoType = 0;
+	delete fRestore;
+	fRestore = NULL;
+	delete fSelection;
+	fSelection = NULL;
+}
+
+void
+ShowImageUndo::Clear()
+{
+	InternalClear();	
+	SendUndoStateMessage(false);
+}
+
+void
+ShowImageUndo::SendUndoStateMessage(bool bCanUndo)
+{
+	if (fWindow) {
+		BMessage msg(MSG_UNDO_STATE);
+		msg.AddBool("can_undo", bCanUndo);
+		BMessenger msgr(fWindow);
+		msgr.SendMessage(&msg);
+	}
+}
+
+void
+ShowImageUndo::SetTo(BRect rect, BBitmap *restore, BBitmap *selection)
+{
+	// NOTE: THIS FUNCTION DOES NOT MAKE COPIES OF THE BITMAPS PASSED TO IT
+	InternalClear();
+	
+	fUndoType = UNDO_UNDO;
+	fRect = rect;
+	fRestore = restore;
+	fSelection = selection;
+	
+	SendUndoStateMessage(true);
+}
+
+void
+ShowImageUndo::Undo(BRect rect, BBitmap *restore, BBitmap *selection)
+{
+	// NOTE: THIS FUNCTION DOES NOT MAKE COPIES OF THE BITMAPS PASSED TO IT
+	fUndoType = UNDO_REDO;
+	fRect = rect;
+	delete fRestore;
+	fRestore = restore;
+	fSelection = selection;
+		// NOTE: fSelection isn't deleted here because ShowImageView
+		// takes ownership of it during an Undo
+}
+

src/apps/showimage/ShowImageUndo.h

@@ -0,0 +1,79 @@
+/*****************************************************************************/
+// ShowImageUndo
+// Written by Michael Wilber
+//
+// ShowImageUndo.h
+//
+//
+// Copyright (c) 2003 OpenBeOS Project
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+// and/or sell copies of the Software, and to permit persons to whom the 
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included 
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+/*****************************************************************************/
+
+#ifndef _ShowImageUndo_h
+#define _ShowImageUndo_h
+
+#include <Rect.h>
+#include <Bitmap.h>
+#include <Window.h>
+#include <Message.h>
+#include <Messenger.h>
+#include "ShowImageConstants.h"
+
+// for Undo
+#define UNDO_UNDO 1
+#define UNDO_REDO 2
+
+class ShowImageUndo {
+public:
+	ShowImageUndo();
+	~ShowImageUndo();
+	
+	void SetWindow(BWindow *win) { fWindow = win; }
+	
+	void Clear();
+	
+	// NOTE: THESE TWO FUNCTIONS DO NOT MAKE COPIES OF THE
+	// BITMAPS PASSED TO THEM
+	void SetTo(BRect rect, BBitmap *restore, BBitmap *selection);
+	void Undo(BRect rect, BBitmap *restore, BBitmap *selection);
+	
+	int32 GetType() { return fUndoType; }
+	BRect GetRect() { return fRect; }
+	BBitmap *GetRestoreBitmap() { return fRestore; }
+	BBitmap *GetSelectionBitmap() { return fSelection; }
+	
+private:
+	void InternalClear();
+	void SendUndoStateMessage(bool bCanUndo);
+	
+	BWindow *fWindow;
+		// Window to which notification messages are sent
+	int32 fUndoType;
+		// Nothing, Undo or Redo
+	BRect fRect;
+		// Area of background bitmap where change took place
+	BBitmap *fRestore;
+		// Changed portion of background bitmap, before change took place
+	BBitmap *fSelection;
+		// Selection present before change took place
+};
+
+#endif /* _ShowImageUndo_h */
+

src/apps/showimage/ShowImageView.cpp

@@ -299,6 +299,7 @@ void ShowImageView::DeleteSelBitmap()
 void
 ShowImageView::SetImage(const entry_ref *pref)
 {
+	fUndo.Clear();
 	DeleteBitmap();
 	SetHasSelection(false);
 	fMakesSelection = false;
@@ -509,6 +510,7 @@ ShowImageView::SetScaleBilinear(bool s)
 void
 ShowImageView::AttachedToWindow()
 {
+	fUndo.SetWindow(Window());
 	FixupScrollBars();
 }
 
@@ -814,6 +816,25 @@ ShowImageView::ConstrainToImage(BRect &rect)
 	rect.SetRightBottom(rightBottom);
 }
 
+BBitmap*
+ShowImageView::CopyFromRect(BRect srcRect)
+{	
+	BRect rect(0, 0, srcRect.Width(), srcRect.Height());
+	BView view(rect, NULL, B_FOLLOW_NONE, B_WILL_DRAW);
+	BBitmap *bitmap = new BBitmap(rect, fBitmap->ColorSpace(), true);
+	if (bitmap == NULL) return NULL;
+	
+	if (bitmap->Lock()) {
+		bitmap->AddChild(&view);
+		view.DrawBitmap(fBitmap, srcRect, rect);
+		view.Sync();
+		bitmap->RemoveChild(&view);
+		bitmap->Unlock();
+	}
+	
+	return bitmap;
+}
+
 BBitmap*
 ShowImageView::CopySelection(uchar alpha, bool imageSize)
 {
@@ -1038,12 +1059,12 @@ ShowImageView::GetMouseButtons()
 }
 
 void
-ShowImageView::GetSelMergeRects(BRect &srcBits, BRect &destRect)
+ShowImageView::GetMergeRects(BBitmap *merge, BRect selection, BRect &srcBits, BRect &destRect)
 {
-	destRect = fSelectionRect;
+	destRect = selection;
 	ConstrainToImage(destRect);
 	
-	srcBits = fSelectionRect;
+	srcBits = selection;
 	if (srcBits.left < 0)
 		srcBits.left = -(srcBits.left);
 	else
@@ -1055,20 +1076,22 @@ ShowImageView::GetSelMergeRects(BRect &srcBits, BRect &destRect)
 	if (srcBits.right > fBitmap->Bounds().right)
 		srcBits.right = srcBits.left + destRect.Width();
 	else
-		srcBits.right = fSelBitmap->Bounds().right;
+		srcBits.right = merge->Bounds().right;
 	if (srcBits.bottom > fBitmap->Bounds().bottom)
 		srcBits.bottom = srcBits.top + destRect.Height();
 	else
-		srcBits.bottom = fSelBitmap->Bounds().bottom;
+		srcBits.bottom = merge->Bounds().bottom;	
 }
 
 void
-ShowImageView::MergeSelection()
+ShowImageView::GetSelMergeRects(BRect &srcBits, BRect &destRect)
 {
-	if (!HasSelection() || !fSelBitmap)
-		return;
+	GetMergeRects(fSelBitmap, fSelectionRect, srcBits, destRect);
+}
 
-	// Merge selection with background
+void
+ShowImageView::MergeWithBitmap(BBitmap *merge, BRect selection)
+{
 	BView view(fBitmap->Bounds(), NULL, B_FOLLOW_NONE, B_WILL_DRAW);
 	BBitmap *bitmap = new BBitmap(fBitmap->Bounds(), fBitmap->ColorSpace(), true);
 	if (bitmap == NULL)
@@ -1077,10 +1100,9 @@ ShowImageView::MergeSelection()
 	if (bitmap->Lock()) {
 		bitmap->AddChild(&view);
 		view.DrawBitmap(fBitmap, fBitmap->Bounds());
-		
 		BRect srcBits, destRect;
-		GetSelMergeRects(srcBits, destRect);
-		view.DrawBitmap(fSelBitmap, srcBits, destRect);
+		GetMergeRects(merge, selection, srcBits, destRect);
+		view.DrawBitmap(merge, srcBits, destRect);
 		
 		view.Sync();
 		bitmap->RemoveChild(&view);
@@ -1095,6 +1117,25 @@ ShowImageView::MergeSelection()
 		delete bitmap;
 }
 
+void
+ShowImageView::MergeSelection()
+{
+	if (!HasSelection())
+		return;
+		
+	if (!fSelBitmap) {
+		// Even though the merge will not change
+		// the background image, I still need to save
+		// some undo information here
+		fUndo.SetTo(fSelectionRect, NULL, CopySelection());
+		return;
+	}
+
+	// Merge selection with background
+	fUndo.SetTo(fSelectionRect, CopyFromRect(fSelectionRect), CopySelection());
+	MergeWithBitmap(fSelBitmap, fSelectionRect);
+}
+
 void
 ShowImageView::MouseDown(BPoint position)
 {
@@ -1485,6 +1526,45 @@ ShowImageView::PageCount()
 	return fDocumentCount;
 }
 
+void
+ShowImageView::Undo()
+{
+	int32 undoType = fUndo.GetType();
+	if (undoType != UNDO_UNDO && undoType != UNDO_REDO)
+		return;
+		
+	// backup current selection
+	BRect undoneSelRect;
+	BBitmap *undoneSelection;
+	undoneSelRect = fSelectionRect;
+	undoneSelection = CopySelection();
+	
+	if (undoType == UNDO_UNDO) {
+		BBitmap *undoRestore;
+		undoRestore = fUndo.GetRestoreBitmap();
+		if (undoRestore)
+			MergeWithBitmap(undoRestore, fUndo.GetRect());
+	}
+		
+	// restore previous image/selection
+	BBitmap *undoSelection;
+	undoSelection = fUndo.GetSelectionBitmap();
+		// NOTE: ShowImageView is responsible for deleting this bitmap
+		// (Which it will, as it would with a fSelBitmap that it allocated itself)
+	if (!undoSelection)
+		SetHasSelection(false);
+	else {
+		SetHasSelection(true);
+		fCopyFromRect = BRect();
+		fSelectionRect = fUndo.GetRect();
+		fSelBitmap = undoSelection;
+	}
+	
+	fUndo.Undo(undoneSelRect, NULL, undoneSelection);
+	
+	Invalidate();
+}
+
 void
 ShowImageView::AddWhiteRect(BRect &rect)
 {

src/apps/showimage/ShowImageView.h

@@ -37,6 +37,7 @@
 #include <TranslatorRoster.h>
 
 #include "Filter.h"
+#include "ShowImageUndo.h"
 
 #define DELAYED_SCALING 1
 
@@ -82,6 +83,7 @@ public:
 	int32 CurrentPage();
 	int32 PageCount();
 	
+	void Undo();
 	void Cut();
 	void Paste();
 	void SelectAll();
@@ -113,6 +115,7 @@ public:
 	void SetIcon(bool clear);
 	
 private:
+	ShowImageUndo fUndo;
 	enum image_orientation {
 		k0,    // 0
 		k90,   // 1
@@ -132,8 +135,10 @@ private:
 	void Notify(const char* status);
 	void AddToRecentDocuments();
 	void AddWhiteRect(BRect &rect);
+	void GetMergeRects(BBitmap *merge, BRect selection, BRect &srcBits, BRect &destRect);
 	void GetSelMergeRects(BRect &srcBits, BRect &destRect);
 	void PasteBitmap(BBitmap *bitmap, BPoint point);
+	void MergeWithBitmap(BBitmap *merge, BRect selection);
 	void MergeSelection();
 	void DeleteScaler();
 	void DeleteBitmap();
@@ -155,6 +160,7 @@ private:
 	bool FirstFile();
 	void ConstrainToImage(BPoint &point);
 	void ConstrainToImage(BRect &rect);
+	BBitmap* CopyFromRect(BRect srcRect);
 	BBitmap* CopySelection(uchar alpha = 255, bool imageSize = true);
 	bool AddSupportedTypes(BMessage* msg, BBitmap* bitmap);
 	void BeginDrag(BPoint sourcePoint);

src/apps/showimage/ShowImageWindow.cpp

@@ -568,6 +568,14 @@ ShowImageWindow::MessageReceived(BMessage *pmsg)
 			break;
 		}
 		
+		case MSG_UNDO_STATE:
+		{
+			bool benable;
+			if (pmsg->FindBool("can_undo", &benable) == B_OK)
+				EnableMenuItem(fBar, B_UNDO, benable);
+			break;
+		}
+		
 		case MSG_CLIPBOARD_CHANGED:
 		{
 			// The app sends this message after it examines
@@ -580,6 +588,7 @@ ShowImageWindow::MessageReceived(BMessage *pmsg)
 		}
 
 		case B_UNDO:
+			fImageView->Undo();
 			break;
 		case B_CUT:
 			fImageView->Cut();