From 5af91ef5cb7c468bc0670caec533cfc8eef7e77f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Fri, 16 Jan 2004 04:52:44 +0000
Subject: [PATCH] Implemented DataEditor::Redo(), and RemoveRedos(); the latter
 will now be called by AddChange(). Fixed ApplyChanges() to only apply changes
 up to (and incl.) the last change; it won't apply all changes anymore.
 DataEditor::Undo() and Redo() now lock themselves. Added some more simple
 tests to DiskProbe.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@6102 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/apps/diskprobe/DataEditor.cpp | 37 +++++++++++++++++++++++++++++--
 src/apps/diskprobe/DiskProbe.cpp  | 23 +++++++++++++++++++
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/src/apps/diskprobe/DataEditor.cpp b/src/apps/diskprobe/DataEditor.cpp
index 3861be2f34..9731f386c6 100644
--- a/src/apps/diskprobe/DataEditor.cpp
+++ b/src/apps/diskprobe/DataEditor.cpp
@@ -248,6 +248,8 @@ DataEditor::AddChange(DataChange *change)
 	if (change == NULL)
 		return;
 
+	RemoveRedos();
+
 	fChanges.AddItem(change);
 	fLastChange = change;
 }
@@ -299,7 +301,10 @@ DataEditor::Insert(off_t offset, const uint8 *text, size_t length)
 void 
 DataEditor::ApplyChanges()
 {
-	int32 count = fChanges.CountItems();
+	if (fLastChange == NULL)
+		return;
+
+	int32 count = fChanges.IndexOf(fLastChange) + 1;
 
 	for (int32 i = 0; i < count; i++) {
 		DataChange *change = fChanges.ItemAt(i);
@@ -308,15 +313,32 @@ DataEditor::ApplyChanges()
 }
 
 
+/** This method will be called by DataEditor::AddChange()
+ *	immediately before a change is applied.
+ *	It removes all pending redo nodes from the list that would
+ *	come after the current change.
+ */
+
 void 
 DataEditor::RemoveRedos()
 {
+	if (fLastChange == NULL)
+		return;
+
+	int32 start = fChanges.IndexOf(fLastChange) + 1;
+
+	for (int32 i = fChanges.CountItems(); i-- > start; ) {
+		DataChange *change = fChanges.RemoveItemAt(i);
+		delete change;
+	}
 }
 
 
 status_t 
 DataEditor::Undo()
 {
+	BAutolock locker(fLock);
+
 	if (!CanUndo())
 		return B_ERROR;
 
@@ -335,6 +357,17 @@ DataEditor::Undo()
 status_t 
 DataEditor::Redo()
 {
+	BAutolock locker(fLock);
+
+	if (!CanRedo())
+		return B_ERROR;
+
+	int32 index = fChanges.IndexOf(fLastChange);
+	fLastChange = fChanges.ItemAt(index + 1);
+
+	fLastChange->Apply(fRealViewOffset, fView, fRealViewSize);
+
+	return B_OK;
 }
 
 
@@ -348,7 +381,7 @@ DataEditor::CanUndo() const
 bool 
 DataEditor::CanRedo() const
 {
-	return fLastChange != NULL && fChanges.IndexOf(fLastChange) < fChanges.CountItems() - 1;
+	return fChanges.IndexOf(fLastChange) < fChanges.CountItems() - 1;
 }
 
 
diff --git a/src/apps/diskprobe/DiskProbe.cpp b/src/apps/diskprobe/DiskProbe.cpp
index 5e6afbf3e9..d0be583886 100644
--- a/src/apps/diskprobe/DiskProbe.cpp
+++ b/src/apps/diskprobe/DiskProbe.cpp
@@ -131,6 +131,29 @@ DiskProbe::DiskProbe()
 	if (printBlock(editor, "undo (location 0):") < B_OK)
 		return;
 
+	status = editor.Redo();
+	if (status < B_OK)
+		fprintf(stderr, "Could not redo: %s\n", strerror(status));
+	if (printBlock(editor, "redo (location 0):") < B_OK)
+		return;
+
+	status = editor.Redo();
+	editor.SetViewOffset(700);
+	if (status < B_OK)
+		fprintf(stderr, "Could not redo: %s\n", strerror(status));
+	if (printBlock(editor, "redo (location 700):") < B_OK)
+		return;
+
+	status = editor.Redo();
+	if (status == B_OK)
+		fprintf(stderr, "Could apply redo (non-expected behaviour)!\n");
+
+	status = editor.Undo();
+	if (status < B_OK)
+		fprintf(stderr, "Could not undo: %s\n", strerror(status));
+	if (printBlock(editor, "undo (location 700):") < B_OK)
+		return;
+
 	PostMessage(B_QUIT_REQUESTED);
 }