From 75b7f5c2fa63bc1ef13ac6fb5f82c7d52bfabd6c Mon Sep 17 00:00:00 2001
From: Eike Hein <hein@kde.org>
Date: Thu, 3 Aug 2017 21:12:14 +0900
Subject: [PATCH] Keep fallback icon updated

Summary:
Windows we can't find an app icon for using the normal means
get the icon used by the windowing system in the Task Manager.
This fallback icon was then not updated when changed on the
window, only occasionally as a side-effect of cache evictions
and model data requests.

This patch notes which windows hit the fallback path, and for
those windows evicts the cache when the icon changes on the
window, causing it to be re-retrieved from the windowing system
as views respond to the dataChanged signal for the decoration
role.

Evicting the entire cache is a little bit costly, but:
- This is a fallback codepath.
- Apps conventionally update title and icon in one go, meaning
  the cache is often already getting evicted anyway.
- Icons don't change that often.

BUG:383017

Reviewers: #plasma, davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D7092
---
 libtaskmanager/xwindowtasksmodel.cpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/libtaskmanager/xwindowtasksmodel.cpp b/libtaskmanager/xwindowtasksmodel.cpp
index d0b3e28d5..1cef6c97d 100644
--- a/libtaskmanager/xwindowtasksmodel.cpp
+++ b/libtaskmanager/xwindowtasksmodel.cpp
@@ -62,6 +62,7 @@ public:
     QHash<WId, KWindowInfo*> windowInfoCache;
     QHash<WId, AppData> appDataCache;
     QHash<WId, QRect> delegateGeometries;
+    QSet<WId> usingFallbackIcon;
     WId activeWindow = -1;
     KSharedConfig::Ptr rulesConfig;
     KDirWatch *configWatcher = nullptr;
@@ -251,6 +252,7 @@ void XWindowTasksModel::Private::removeWindow(WId window)
         transientsDemandingAttention.remove(window);
         windowInfoCache.remove(window);
         appDataCache.remove(window);
+        usingFallbackIcon.remove(window);
         delegateGeometries.remove(window);
         q->endRemoveRows();
     } else { // Could be a transient.
@@ -329,8 +331,12 @@ void XWindowTasksModel::Private::windowChanged(WId window, NET::Properties prope
         changedRoles << Qt::DisplayRole << Qt::DecorationRole << AppId << AppName << GenericName << LauncherUrl << AppPid;
     }
 
-    if ((properties & NET::WMIcon) && !changedRoles.contains(Qt::DecorationRole)) {
-        changedRoles << Qt::DecorationRole;
+    if ((properties & NET::WMIcon) && usingFallbackIcon.contains(window)) {
+        wipeAppDataCache = true;
+
+        if (!changedRoles.contains(Qt::DecorationRole)) {
+            changedRoles << Qt::DecorationRole;
+        }
     }
 
     // FIXME TODO: It might be worth keeping track of which windows were demanding
@@ -374,6 +380,7 @@ void XWindowTasksModel::Private::windowChanged(WId window, NET::Properties prope
 
     if (wipeAppDataCache) {
         appDataCache.remove(window);
+        usingFallbackIcon.remove(window);
     }
 
     if (!changedRoles.isEmpty()) {
@@ -452,6 +459,7 @@ QIcon XWindowTasksModel::Private::icon(WId window)
     icon.addPixmap(KWindowSystem::icon(window, KIconLoader::SizeLarge, KIconLoader::SizeLarge, false));
 
     appDataCache[window].icon = icon;
+    usingFallbackIcon.insert(window);
 
     return icon;
 }