Is there an easy way to add Overwrite to a Blend Mode menu?

[MJW]

I'd like to add an Overwrite option to a Blend Mode menu, and I'm not sure the best way to do it. I want a menu like the Paint Bucket and other such tools use, where the final option is Overwrite.

 

I must admit I don't really understand all that's going on with the code that creates and configures the menu, some of which looks like this:

 

            // setup for a user selected blend mode
            IEnumLocalizerFactory factory = Services.GetService<IEnumLocalizerFactory>();
            IEnumLocalizer blendModeLocalizer = factory.Create(typeof(LayerBlendMode));
            IList<ILocalizedEnumValue> blendModes = blendModeLocalizer.GetLocalizedEnumValues();
            object[] blendModesArray = blendModes.Select(lev => lev.EnumValue).ToArrayEx();
            int defaultBlendModeIndex = blendModesArray.IndexOf(LayerBlendMode.Normal);

 

 

I do know, though, that it uses enumerations and such that don't include Overwrite. I'm hoping there's some reasonably simpe way to add the option to a menu while still being compatible with the standard method of creating the Blend Mode drop-down-list control.

[Rick Brewster]

Not really. Overwrite can't work like a regular blend mode, it requires an additional alpha channel; it needs to know which pixels to overwrite and by how much. Without that it's just copy/replace.

[MJW]

In my case, copy/replace is all I want to do; however, if that's not what Overwrite does, calling my mode Overwrite would probably be misleading. I thought all Overwrite does is replace the RGB and alpha of the old pixel with with the new pixel -- something that's simpler, not more complex, than the other blend modes.

 

EDIT: Though it's actually for a different plugin, I'll use my Paste From Clipboard plugin to illustrate. The plugin normally copies the clipboard image to the canvas. It has an option to blend it with the canvas instead. Currently, there's a checkbox that switches it from the normal mode of replacing the destination pixels to blending with the pixels. The checkbox enables the Blend Mode control. I'd like to replace the checkbox with an "Overwrite" (or perhaps, "Replace") selection in the drop-down menu, which would be the default.

[Rick Brewster]

I would call it Replace

 

StaticListChoiceProperty takes an object[] so it can use whatever values you want, even mixed-type enum values. You'll just have to do type checking when reading the value. So create a List<object>, populate it with the LayerBlendModes, and then add another value, anything you want really, to use for Replace.

[MJW]

Thanks a lot, Rick!