[polari] roomStack: Expose :view-height to window

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

commit 19d9d0f21c0617308ca8bb969d11833a02fb25eb
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Aug 23 23:52:46 2021 +0200

    roomStack: Expose :view-height to window
    
    This allows the main window to just forward the property, instead of
    using the ::size-allocate signal to compute it itself.
    
    Part-of: <https://gitlab.gnome.org/GNOME/polari/-/merge_requests/225>

 src/mainWindow.js | 17 +++--------------
 src/roomStack.js  | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 14 deletions(-)
---
diff --git a/src/mainWindow.js b/src/mainWindow.js
index a7c3d539..8e529256 100644
--- a/src/mainWindow.js
+++ b/src/mainWindow.js
@@ -142,15 +142,8 @@ export default GObject.registerClass({
         if (GLib.get_application_name().toLowerCase().includes('snapshot'))
             this.get_style_context().add_class('snapshot');
 
-        this._viewHeight = this._calculateViewHeight();
-        this._roomStack.connect('size-allocate', () => {
-            let oldViewHeight = this._viewHeight;
-            let newViewHeight = this._calculateViewHeight();
-            if (oldViewHeight !== newViewHeight) {
-                this._viewHeight = newViewHeight;
-                this.notify('view-height');
-            }
-        });
+        this._roomStack.connect('notify::view-height',
+            () => this.notify('view-height'));
 
         // command output notifications should not pop up over
         // the input area, but appear to emerge from it, so
@@ -227,13 +220,9 @@ export default GObject.registerClass({
         return this._subtitle.length > 0;
     }
 
-    _calculateViewHeight() {
-        return this._roomStack.get_allocated_height() - this._roomStack.entry_area_height;
-    }
-
     // eslint-disable-next-line camelcase
     get view_height() {
-        return this._viewHeight;
+        return this._roomStack.view_height;
     }
 
     _onAccountsReachableChanged() {
diff --git a/src/roomStack.js b/src/roomStack.js
index 872f752a..4d29be70 100644
--- a/src/roomStack.js
+++ b/src/roomStack.js
@@ -16,6 +16,10 @@ export default GObject.registerClass({
             'entry-area-height', 'entry-area-height', 'entry-area-height',
             GObject.ParamFlags.READABLE,
             0, GLib.MAXUINT32, 0),
+        'view-height': GObject.ParamSpec.uint(
+            'view-height', 'view-height', 'view-height',
+            GObject.ParamFlags.READABLE,
+            0, GLib.MAXUINT32, 0),
     },
 }, class RoomStack extends Gtk.Stack {
     _init(params) {
@@ -35,6 +39,7 @@ export default GObject.registerClass({
         this.add_named(new ChatPlaceholder(this._sizeGroup), 'placeholder');
 
         this._entryAreaHeight = 0;
+        this._viewHeight = 0;
 
         this.connect('destroy', () => {
             this._roomManager.disconnect(this._roomAddedId);
@@ -64,6 +69,12 @@ export default GObject.registerClass({
             this._entryAreaHeight = entryHeight;
             this.notify('entry-area-height');
         }
+
+        const viewHeight = this.get_allocated_height() - entryHeight;
+        if (this._viewHeight !== viewHeight) {
+            this._viewHeight = viewHeight;
+            this.notify('view-height');
+        }
     }
 
     // eslint-disable-next-line camelcase
@@ -71,6 +82,11 @@ export default GObject.registerClass({
         return this._entryAreaHeight;
     }
 
+    // eslint-disable-next-line camelcase
+    get view_height() {
+        return this._viewHeight;
+    }
+
     _addView(id, view) {
         this._rooms.set(id, view);
         this.add_named(view, id);