Window drag with PostMessage 0xA1 and WebView

[Tvlao]

This window drag code works. The window is dragged.

Code: Select all

TGui := Gui('+Resize')
TGui.Title := "TGui"
TGui.Show("w300 h100")

OnMessage(0x0201, WM_LBUTTONDOWN)

WM_LBUTTONDOWN(wParam, lParam, msg, hwnd) {
    if wParam = 1{
        PostMessage 0xA1, 2,,, TGui.Hwnd
    }
}

But if you load WebView into a window, then this window can no longer be dragged.

Code: Select all

TGui := Gui('+Resize')
TGui.Title := "TGui"
TGui.Show("w300 h100")
wvc := WebView2.create(TGui.Hwnd)
wv := wvc.CoreWebView2
wv.Navigate('file:///' . A_ScriptDir . '/test.html')

OnMessage(0x0201, WM_LBUTTONDOWN)

WM_LBUTTONDOWN(wParam, lParam, msg, hwnd) {
    if wParam = 1{
        PostMessage 0xA1, 2,,, TGui.Hwnd
    }
}

[Tvlao]

This is from here: https://github.com/thqby/ahk2_lib/blob/master/WebView2/WebView2.ahk

Is this a library bug? Or is there no way to move the window when WebView is loaded?

[william_ahk]

It's not a bug. Edge WebView2 is a separate window and process glued to the AHK's Gui window. So OnMessage cannot listen for messages from other processes. Fortunately Microsoft has already implemented this. You can use css rules to set a draggable region, it's actually easier than handling barebone window messages.

First enable the feature in the flags:

Code: Select all

wvc := WebView2.create(MyGui.Hwnd,,,,, { AdditionalBrowserArguments: "--enable-features=msWebView2EnableDraggableRegions" })

Then define the regions in the css.

Code: Select all

<style>
    body {
        --app-region: drag;
        -webkit-app-region: drag;
    }
    #app {
        --app-region: no-drag;
        -webkit-app-region: no-drag;
    }
</style>
<div id="app">
    <input type="text" />
</div>