From 6099e92df59c29f1f3f9ecd49af8caeecd787bfa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Sat, 1 Sep 2018 18:57:59 +0200
Subject: [PATCH] workspace: Confine caption width to workspace area

When we started to only show a single caption at a time, we allowed
title captions to be wider than their corresponding window preview.
But while overlapping neighboring previews is fine, we shouldn't
allow the captions to leak outside the workspace area itself and
overlap unrelated elements like workspace switcher or dash.

This partly reverts commit b3b30f239d.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/214
---
 js/ui/workspace.js | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index ddf343e77..97c2d3a58 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -465,6 +465,8 @@ var WindowOverlay = new Lang.Class({
         title.clutter_text.ellipsize = Pango.EllipsizeMode.END;
         windowClone.actor.label_actor = title;
 
+        this._maxTitleWidth = -1;
+
         this._updateCaptionId = metaWindow.connect('notify::title', w => {
             this.title.text = this._getCaption();
             this.relayout(false);
@@ -527,6 +529,13 @@ var WindowOverlay = new Lang.Class({
                 Math.max(this.borderSize, this.closeButton.width - this.closeButton._overlap)];
     },
 
+    setMaxChromeWidth(max) {
+        if (this._maxTitleWidth == max)
+            return;
+
+        this._maxTitleWidth = max;
+    },
+
     relayout(animate) {
         let button = this.closeButton;
         let title = this.title;
@@ -553,13 +562,26 @@ var WindowOverlay = new Lang.Class({
         else
             button.set_position(Math.floor(buttonX), Math.floor(buttonY));
 
-        let titleX = cloneX + (cloneWidth - title.width) / 2;
+        // Clutter.Actor.get_preferred_width() will return the fixed width if
+        // one is set, so we need to reset the width by calling set_width(-1),
+        // to forward the call down to StLabel.
+        // We also need to save and restore the current width, otherwise the
+        // animation starts from the wrong point.
+        let prevTitleWidth = title.width;
+        title.set_width(-1);
+
+        let [titleMinWidth, titleNatWidth] = title.get_preferred_width(-1);
+        let titleWidth = Math.max(titleMinWidth,
+                                  Math.min(titleNatWidth, this._maxTitleWidth));
+        title.width = prevTitleWidth;
+
+        let titleX = cloneX + (cloneWidth - titleWidth) / 2;
         let titleY = cloneY + cloneHeight - (title.height - this.borderSize) / 2;
 
         if (animate) {
-            this._animateOverlayActor(title, Math.floor(titleX), Math.floor(titleY), title.width);
+            this._animateOverlayActor(title, Math.floor(titleX), Math.floor(titleY), titleWidth);
         } else {
-            title.width = title.width;
+            title.width = titleWidth;
             title.set_position(Math.floor(titleX), Math.floor(titleY));
         }
 
@@ -1305,6 +1327,12 @@ var Workspace = new Lang.Class({
             let cloneHeight = clone.actor.height * scale;
             clone.slot = [x, y, cloneWidth, cloneHeight];
 
+            let cloneCenter = x + cloneWidth / 2;
+            let maxChromeWidth = 2 * Math.min(
+                cloneCenter - area.x,
+                area.x + area.width - cloneCenter);
+            overlay.setMaxChromeWidth(Math.round(maxChromeWidth));
+
             if (overlay && (initialPositioning || !clone.positioned))
                 overlay.hide();