From 7d9054f74ee2d2fba63c442f444fc8a276ca0f1d Mon Sep 17 00:00:00 2001
From: Devin Lin <espidev@gmail.com>
Date: Thu, 13 Feb 2025 11:39:28 -0500
Subject: [PATCH] applicationlistmodel: Space out application list refreshes

Use the same behavior as kickoff on desktop, to limit application list
refreshes to once every 100ms.

https://invent.kde.org/plasma/plasma-mobile/-/issues/440
---
 .../folio/applicationlistmodel.cpp            | 23 +++++++++++++------
 .../homescreens/folio/applicationlistmodel.h  |  2 ++
 .../halcyon/plugin/applicationlistmodel.cpp   | 23 +++++++++++++------
 .../halcyon/plugin/applicationlistmodel.h     |  2 ++
 4 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/containments/homescreens/folio/applicationlistmodel.cpp b/containments/homescreens/folio/applicationlistmodel.cpp
index 4a517876..c3953239 100644
--- a/containments/homescreens/folio/applicationlistmodel.cpp
+++ b/containments/homescreens/folio/applicationlistmodel.cpp
@@ -18,10 +18,19 @@
 #include <KSharedConfig>
 #include <KSycoca>
 
+#include <chrono>
+
+using namespace std::chrono_literals;
+
 ApplicationListModel::ApplicationListModel(HomeScreen *parent)
     : QAbstractListModel(parent)
+    , m_reloadAppsTimer{new QTimer{this}}
 {
-    connect(KSycoca::self(), &KSycoca::databaseChanged, this, &ApplicationListModel::sycocaDbChanged);
+    m_reloadAppsTimer->setSingleShot(true);
+    m_reloadAppsTimer->setInterval(100ms);
+    connect(m_reloadAppsTimer, &QTimer::timeout, this, &ApplicationListModel::sycocaDbChanged);
+
+    connect(KSycoca::self(), &KSycoca::databaseChanged, m_reloadAppsTimer, static_cast<void (QTimer::*)()>(&QTimer::start));
 
     // initialize wayland window checking
     KWayland::Client::ConnectionThread *connection = KWayland::Client::ConnectionThread::fromApplication(this);
@@ -51,12 +60,6 @@ void ApplicationListModel::load()
 
     const QStringList blacklist = blgroup.readEntry("blacklist", QStringList());
 
-    beginResetModel();
-
-    m_delegates.clear();
-
-    QList<FolioDelegate *> unorderedList;
-
     auto filter = [blacklist](const KService::Ptr &service) -> bool {
         if (service->noDisplay()) {
             return false;
@@ -73,6 +76,12 @@ void ApplicationListModel::load()
         return true;
     };
 
+    beginResetModel();
+
+    m_delegates.clear();
+
+    QList<FolioDelegate *> unorderedList;
+
     const KService::List apps = KApplicationTrader::query(filter);
 
     for (const KService::Ptr &service : apps) {
diff --git a/containments/homescreens/folio/applicationlistmodel.h b/containments/homescreens/folio/applicationlistmodel.h
index 15a2ae9b..5e3a0ed0 100644
--- a/containments/homescreens/folio/applicationlistmodel.h
+++ b/containments/homescreens/folio/applicationlistmodel.h
@@ -44,6 +44,8 @@ public Q_SLOTS:
 protected:
     HomeScreen *m_homeScreen{nullptr};
     QList<FolioDelegate *> m_delegates;
+
+    QTimer *m_reloadAppsTimer{nullptr};
 };
 
 class ApplicationListSearchModel : public QSortFilterProxyModel
diff --git a/containments/homescreens/halcyon/plugin/applicationlistmodel.cpp b/containments/homescreens/halcyon/plugin/applicationlistmodel.cpp
index 1ede6712..ca6bf299 100644
--- a/containments/homescreens/halcyon/plugin/applicationlistmodel.cpp
+++ b/containments/homescreens/halcyon/plugin/applicationlistmodel.cpp
@@ -18,10 +18,19 @@
 #include <KSharedConfig>
 #include <KSycoca>
 
+#include <chrono>
+
+using namespace std::chrono_literals;
+
 ApplicationListModel::ApplicationListModel(QObject *parent)
     : QAbstractListModel(parent)
+    , m_reloadAppsTimer{new QTimer{this}}
 {
-    connect(KSycoca::self(), &KSycoca::databaseChanged, this, &ApplicationListModel::sycocaDbChanged);
+    m_reloadAppsTimer->setSingleShot(true);
+    m_reloadAppsTimer->setInterval(100ms);
+    connect(m_reloadAppsTimer, &QTimer::timeout, this, &ApplicationListModel::sycocaDbChanged);
+
+    connect(KSycoca::self(), &KSycoca::databaseChanged, m_reloadAppsTimer, static_cast<void (QTimer::*)()>(&QTimer::start));
 }
 
 ApplicationListModel::~ApplicationListModel() = default;
@@ -49,12 +58,6 @@ void ApplicationListModel::loadApplications()
 
     const QStringList blacklist = blgroup.readEntry("blacklist", QStringList());
 
-    beginResetModel();
-
-    m_applicationList.clear();
-
-    QList<Application *> unorderedList;
-
     auto filter = [blacklist](const KService::Ptr &service) -> bool {
         if (service->noDisplay()) {
             return false;
@@ -71,6 +74,12 @@ void ApplicationListModel::loadApplications()
         return true;
     };
 
+    beginResetModel();
+
+    m_applicationList.clear();
+
+    QList<Application *> unorderedList;
+
     const KService::List apps = KApplicationTrader::query(filter);
 
     for (const KService::Ptr &service : apps) {
diff --git a/containments/homescreens/halcyon/plugin/applicationlistmodel.h b/containments/homescreens/halcyon/plugin/applicationlistmodel.h
index 167ed6f6..0bebcfed 100644
--- a/containments/homescreens/halcyon/plugin/applicationlistmodel.h
+++ b/containments/homescreens/halcyon/plugin/applicationlistmodel.h
@@ -11,6 +11,7 @@
 #include <QObject>
 #include <QQuickItem>
 #include <QSet>
+#include <QTimer>
 
 /**
  * @short The base application list, used directly by the full app list page.
@@ -37,4 +38,5 @@ public Q_SLOTS:
 
 protected:
     QList<Application *> m_applicationList;
+    QTimer *m_reloadAppsTimer{nullptr};
 };