undo-redo

While creating a customized editor with RichTextBox, I've face the problem of finding deleted/inserted text with the provided information with TextChanged event. The instance of TextChangedEventArgs has some useful data, but I guess it does not cover all the needs. Suppose a scenario which multiple paragraphs are inserted, and at the same time, the selected text (which itself spanned multiple paragraphs) has been deleted. With the instance of TextChangedEventArgs, you have a collection of text changes, and each change only provides you with the number of removed or added symbols and the

I created a simple demo app with a NSTextView and a button, the provided a NSTextViewDelegate to the textView and added an action: - (IBAction)actionButtonClicked:(id)sender { NSString *oldText = [[[self.textView textStorage] string] copy]; NSString *newText = @"And... ACTION!"; [[self.textView undoManager] registerUndoWithTarget:self.textView selector:@selector(setString:) object:oldText]; [[self.textView undoManager] setActionName:@"ACTION"]; [self.textView setString:newText]; } Undo/redo works without problems, if I change text by hand. But if I change the text with the action method, undo

I'm playing with quite simple interface with buttons and shortcuts for adding, inserting and removing rows of datagrid (underlying bound collection). There's also a need to implement undo stack. But...I have no idea how to do with internal logic of this control. By default DataGrid can remove or add new row automatically and performs many other things on user input (Esc,F2 and so on) thus implicitly changing the bound data. As commands are to be executed on the VM side undo stack is its (or even M's) business either, yet DataGrid contains internally predefined bindings to DataGrid. commands.

I'm writing a desktop application to do vector drawing in C++, and considering using sqlite to back my undo/redo feature. Has anybody used sqlite for undo/redo features? How does it work out for you? Clarification: I was aware of the stack approach, I have even implemented one application with that approach. The problem I encountered was that it becomes hard to maintain after a while. What I meant by utilizing sqlite is that I will map my entire in-memory data structure into a sqlite database, and let the sqlite do the diff and revision for me. Speed should not be a issue if I create a in

I would like to implement undo/redo in a small paint application . It seems the Command Pattern fits the use nicely, but I am unsure how to best implement it. As I understand the pattern, it is necessary to include in each command: The details of the paint operation for purposes of redo (e.g. Line -> start & end points, free form line -> GeneralPath ) The state of the component prior to the change for undo. In this case, that will be a small snapshot image of the area affected by the command. My understanding based on that is that each command needs to be 'atomic' or self contained, with all

The default IntelliJ / Android Studio "Redo" action shortcut is CTRL + Shift + Z and this is a common problem for Windows users. A bigger problem is CTRL + Y is mapped to the "Delete line" action - and this causes the undo stack to be lost. To solve this issue, how can the "Redo" shortcut be changed to CTRL + Y in IntelliJ? İsmail Yavuz Open Settings (press CTRL + ALT + S ) Click Keymap on the left list. There is a combobox that contains keymaps. Select one of them (default means IntelliJ of course. We can't change any of pre-defined keymap however we can copy, edit and then use the edited one