gImageReader unsaved-output dialog needs "Cancel" button, clearer labeling

[ferdnyc]

The current "Output not saved" dialog box's challenge is somewhat confusing, which could lead to accidental loss of work. Especially since it fails to account for situations where the user accidentally attempted to close the program, and does not actually wish to exit.

The current challenge reads "Save output before proceeding?" (To "proceed" in this context would mean to exit the application, which seems contradictory.) The two choices are "No" and "Yes". Selecting "Yes" displays a Save File dialog, whereas choosing "No" immediately closes the program and destroys any unsaved work.

From the perspective of an "Are you sure?" warning, the choices and their effect again seem somewhat reversed. "No" should be the safer option, and prevent the dangerous action from being taken. There's also no option to abort an accidental quit attempt; to return to the application and continue working, the user has to realize that they must first choose "Yes", then cancel the resulting Save dialog.

The confirmation would be more intuitive, and reduce the chances of work accidentally being lost, if it was presented as an "Are you sure?"-style confirmation dialog. The user should have to explicitly indicate, "Yes, I really wish to discard my unsaved work" in order to do so. For all other actions, the application should remain open while the user either saves their progress or returns to working with the software.

LibreOffice displays a dialog with three options, allowing the user to either:

• Explicitly "Close without saving", confirming that they wish to discard their unsaved work
• "Cancel", which dismisses the dialog and returns to the application
• "Save", which brings up the Save File window

[manisandro]

So the thing here is that the same dialog is used for both when the program is closed as well as when the output pane is closed. So "proceeding" refers to the action of either closing the program or closing just the output pane. Using "Save output before closing?" would be confusing in the case where only the output pane is closed, since the user might think that the entire program is about to be closed. The alternative I see would be to just eliminate the "before proceeding", but in my opinion the text isn't that much of an issue.

It is true however that a cancel button is useful, and to make the choices to the user clearer, I've also renamed "Yes" to "Save" and "No" to "Discard".