[polari] mainWindow: Ensure user-list button is at least as wide as high

[Marge Bot <marge-bot src gnome org>]

commit 91a2493df0a68c657c1a33627184db003f0c6565
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Aug 20 06:13:23 2021 +0200

    mainWindow: Ensure user-list button is at least as wide as high
    
    For rooms with few users, the button looks too narrow. We used to use
    a ::size-allocate hack to make the button at least as wide as icon
    buttons, now in GTK4 we can use a cleaner approach and implement a small
    layout manager that requests a width that is at least equal to the height.
    
    Part-of: <https://gitlab.gnome.org/GNOME/polari/-/merge_requests/235>

 src/mainWindow.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
---
diff --git a/src/mainWindow.js b/src/mainWindow.js
index d3f7a86e..32f29251 100644
--- a/src/mainWindow.js
+++ b/src/mainWindow.js
@@ -77,6 +77,20 @@ export const FixedSizeFrame = GObject.registerClass({
     }
 });
 
+export const HeaderBarButtonLayout = GObject.registerClass(
+class ButtonBinLayout extends Gtk.BinLayout {
+    vfunc_measure(widget, orientation, forSize) {
+        const [min, nat] = super.vfunc_measure(widget, orientation, forSize);
+        if (orientation === Gtk.Orientation.VERTICAL)
+            return [min, nat, -1, -1];
+
+        let [, height] = widget.measure(Gtk.Orientation.VERTICAL, -1);
+        const padding = widget.get_style_context().get_padding();
+        height -= padding.left + padding.right;
+        return [min, Math.max(nat, height), -1, -1];
+    }
+});
+
 export default GObject.registerClass({
     Template: 'resource:///org/gnome/Polari/ui/main-window.ui',
     InternalChildren: [
@@ -157,6 +171,9 @@ export default GObject.registerClass({
             this._commandOutputQueue, 'margin-bottom',
             GObject.BindingFlags.SYNC_CREATE);
 
+        // Make sure user-list button is at least as wide as icon buttons
+        this._showUserListButton.layout_manager = new HeaderBarButtonLayout();
+
         this._accountsMonitor = AccountsMonitor.getDefault();
         this._accountsChangedId = this._accountsMonitor.connect(
             'accounts-changed', this._onAccountsChanged.bind(this));