Wails Enhancement Proposal (WEP)

Customising Window Controls in Wails

Author: Lea Anthony Created: 2024-05-20

Summary

This is a proposal for an API to control the appearance and functionality of window controls in Wails. This will only be available on Windows and macOS.

Motivation

We currently do not fully support the ability to customise window controls.

Detailed Design

Controlling Button State

1. A new enum will be added:

      type ButtonState int

      const (
          ButtonEnabled  ButtonState = 0
          ButtonDisabled ButtonState = 1
          ButtonHidden   ButtonState = 2
      )

2. These options will be added to the WebviewWindowOptions option struct:

   MinimiseButtonState ButtonState
   MaximiseButtonState ButtonState
   CloseButtonState    ButtonState

3. These options will be removed from the current Windows/Mac options:

• DisableMinimiseButton
• DisableMaximiseButton
• DisableCloseButton

4. These methods will be added to the Window interface:

   SetMinimizeButtonState(state ButtonState)
   SetMaximizeButtonState(state ButtonState)
   SetCloseButtonState(state ButtonState)

The settings translate to the following functionality on each platform:

Note: On Windows, it is not possible to hide the Min/Max buttons individually. However, disabling both will hide both of the controls and only show the close button.

Controlling Window Style (Windows)

As Windows currently does not have much in the way of controlling the style of the titlebar, a new option will be added to the WebviewWindowOptions option struct:

   ExStyle int

If this is set, then the new Window will use the style specified in the ExStyle field.

Example:

package main

import (
	"github.com/wailsapp/wails/v3/pkg/application"
	"github.com/wailsapp/wails/v3/pkg/w32"
)

func main() {
    app := application.New(application.Options{
		Name:        "My Application",
	})
	
    app.NewWebviewWindowWithOptions(application.WebviewWindowOptions{
        Windows: application.WindowsWindow{
            ExStyle: w32.WS_EX_TOOLWINDOW | w32.WS_EX_NOREDIRECTIONBITMAP | w32.WS_EX_TOPMOST,
        },
	})
	
	app.Run()
}

Pros/Cons

Pros

• We bring much needed customisation capabilities to both macOS and Windows

Cons

• Windows works slightly different to macOS
• No Linux support (doesn't look like it's possible regardless of the solution)

Alternatives Considered

The alternative is to draw your own titlebar, but this is a lot of work and often doesn't look good.

Backwards Compatibility

This is not backwards compatible as we remove the old "disable button" options.

Test Plan

As part of the implementation, the window example will be updated to test the functionality.

Reference Implementation

There is a reference implementation as part of this proposal.

Maintenance Plan

This feature will be maintained and supported by the Wails developers.

Conclusion

This API would be a leap forward in giving developers greater control over their application window appearances.