[effects/showpaint] Use a shortcut to toggle the effect

Summary:
The Show Paint effect is useful when debugging repaint regions issued by
effects. The only headache with it is necessity to enable/disable it.
Consider the following workflow:

* Do some change to an effect;
* Compile KWin (or the effect);
* Go to System Settings and enable the Show Paint effect;
* Test effect, check repaint regions, etc;
* Disable the Show Paint effect;
* Go to the step 1.

This workflow is really exhausting. Also, when testing repaints in a
nested compositor, things become quite messy.

Because purpose of this effect is to debug repaints (and because this
effect is not meant for daily usage), I think that's fine to change
how it's activated.

This patch improves the workflow by changing the way how this effect
gets activated. Instead of enabling/disabling it, one can just use a shortcut
to activate or deactivate the effect.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: broulik, davidedmundson, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D15703

effects/CMakeLists.txt

@@ -92,6 +92,7 @@ set( kwin4_effect_builtins_sources
     resize/resize.cpp
     scale/scale.cpp
     showfps/showfps.cpp
+    showpaint/showpaint.cpp
     slide/slide.cpp
     thumbnailaside/thumbnailaside.cpp
     touchpoints/touchpoints.cpp
@@ -160,7 +161,7 @@ add_subdirectory( presentwindows )
 add_subdirectory( resize )
 include( screenedge/CMakeLists.txt )
 add_subdirectory( showfps )
-include( showpaint/CMakeLists.txt )
+add_subdirectory( showpaint )
 add_subdirectory( slide )
 include( slideback/CMakeLists.txt )
 include( slidingpopups/CMakeLists.txt )

effects/showpaint/CMakeLists.txt

@@ -1,7 +1,25 @@
 #######################################
-# Effect
 
-# Source files
-set( kwin4_effect_builtins_sources ${kwin4_effect_builtins_sources}
-    showpaint/showpaint.cpp
-    )
+# Config
+set(kwin_showpaint_config_SRCS showpaint_config.cpp)
+ki18n_wrap_ui(kwin_showpaint_config_SRCS showpaint_config.ui)
+
+add_library(kwin_showpaint_config MODULE ${kwin_showpaint_config_SRCS})
+
+target_link_libraries(kwin_showpaint_config
+    KF5::ConfigWidgets
+    KF5::GlobalAccel
+    KF5::I18n
+    KF5::Service
+    KF5::XmlGui
+)
+
+kcoreaddons_desktop_to_json(kwin_showpaint_config showpaint_config.desktop SERVICE_TYPES kcmodule.desktop)
+
+install(
+    TARGETS
+        kwin_showpaint_config
+
+    DESTINATION
+        ${PLUGIN_INSTALL_DIR}/kwin/effects/configs
+)

effects/showpaint/showpaint.cpp

@@ -26,6 +26,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <xcb/render.h>
 #endif
 
+#include <KGlobalAccel>
+#include <KLocalizedString>
+
+#include <QAction>
 #include <QPainter>
 
 namespace KWin
@@ -42,6 +46,18 @@ static const QVector<QColor> s_colors {
     Qt::gray
 };
 
+ShowPaintEffect::ShowPaintEffect()
+{
+    auto *toggleAction = new QAction(this);
+    toggleAction->setObjectName(QStringLiteral("Toggle"));
+    toggleAction->setText(i18n("Toggle Show Paint"));
+    KGlobalAccel::self()->setDefaultShortcut(toggleAction, {});
+    KGlobalAccel::self()->setShortcut(toggleAction, {});
+    effects->registerGlobalShortcut({}, toggleAction);
+
+    connect(toggleAction, &QAction::triggered, this, &ShowPaintEffect::toggle);
+}
+
 void ShowPaintEffect::paintScreen(int mask, QRegion region, ScreenPaintData &data)
 {
     m_painted = QRegion();
@@ -123,4 +139,15 @@ void ShowPaintEffect::paintQPainter()
     }
 }
 
+bool ShowPaintEffect::isActive() const
+{
+    return m_active;
+}
+
+void ShowPaintEffect::toggle()
+{
+    m_active = !m_active;
+    effects->addRepaintFull();
+}
+
 } // namespace KWin

effects/showpaint/showpaint.h

@@ -31,14 +31,22 @@ class ShowPaintEffect : public Effect
     Q_OBJECT
 
 public:
+    ShowPaintEffect();
+
     void paintScreen(int mask, QRegion region, ScreenPaintData &data) override;
     void paintWindow(EffectWindow *w, int mask, QRegion region, WindowPaintData &data) override;
 
+    bool isActive() const override;
+
+private Q_SLOTS:
+    void toggle();
+
 private:
     void paintGL(const QMatrix4x4 &projection);
     void paintXrender();
     void paintQPainter();
 
+    bool m_active = false;
     QRegion m_painted; // what's painted in one pass
     int m_colorIndex = 0;
 };

effects/showpaint/showpaint_config.cpp

@@ -0,0 +1,87 @@
+/********************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2018 Vlad Zagorodniy <vladzzag@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+
+#include "showpaint_config.h"
+
+#include <KAboutData>
+#include <KActionCollection>
+#include <KGlobalAccel>
+#include <KLocalizedString>
+#include <KPluginFactory>
+#include <KShortcutsEditor>
+
+#include <QAction>
+
+K_PLUGIN_FACTORY_WITH_JSON(ShowPaintEffectConfigFactory,
+                           "showpaint_config.json",
+                           registerPlugin<KWin::ShowPaintEffectConfig>();)
+
+namespace KWin
+{
+
+ShowPaintEffectConfig::ShowPaintEffectConfig(QWidget *parent, const QVariantList &args)
+    : KCModule(KAboutData::pluginData(QStringLiteral("showpaint")), parent, args)
+    , m_ui(new Ui::ShowPaintEffectConfig)
+{
+    m_ui->setupUi(this);
+
+    auto *actionCollection = new KActionCollection(this, QStringLiteral("kwin"));
+
+    actionCollection->setComponentDisplayName(i18n("KWin"));
+    actionCollection->setConfigGroup(QStringLiteral("ShowPaint"));
+    actionCollection->setConfigGlobal(true);
+
+    QAction *toggleAction = actionCollection->addAction(QStringLiteral("Toggle"));
+    toggleAction->setText(i18n("Toggle Show Paint"));
+    toggleAction->setProperty("isConfigurationAction", true);
+    KGlobalAccel::self()->setDefaultShortcut(toggleAction, {});
+    KGlobalAccel::self()->setShortcut(toggleAction, {});
+
+    m_ui->shortcutsEditor->addCollection(actionCollection);
+
+    connect(m_ui->shortcutsEditor, &KShortcutsEditor::keyChange,
+            this, qOverload<>(&ShowPaintEffectConfig::changed));
+
+    load();
+}
+
+ShowPaintEffectConfig::~ShowPaintEffectConfig()
+{
+    // If save() is called, undoChanges() has no effect.
+    m_ui->shortcutsEditor->undoChanges();
+
+    delete m_ui;
+}
+
+void ShowPaintEffectConfig::save()
+{
+    KCModule::save();
+    m_ui->shortcutsEditor->save();
+}
+
+void ShowPaintEffectConfig::defaults()
+{
+    m_ui->shortcutsEditor->allDefault();
+    KCModule::defaults();
+}
+
+} // namespace KWin
+
+#include "showpaint_config.moc"

effects/showpaint/showpaint_config.desktop

@@ -0,0 +1,8 @@
+[Desktop Entry]
+Type=Service
+X-KDE-ServiceTypes=KCModule
+
+X-KDE-Library=kwin_showpaint_config
+X-KDE-ParentComponents=showpaint
+
+Name=Show Paint

effects/showpaint/showpaint_config.h

@@ -0,0 +1,46 @@
+/********************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2018 Vlad Zagorodniy <vladzzag@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+
+#pragma once
+
+#include <KCModule>
+
+#include "ui_showpaint_config.h"
+
+namespace KWin
+{
+
+class ShowPaintEffectConfig : public KCModule
+{
+    Q_OBJECT
+
+public:
+    explicit ShowPaintEffectConfig(QWidget *parent = nullptr, const QVariantList &args = {});
+    ~ShowPaintEffectConfig() override;
+
+public Q_SLOTS:
+    void save() override;
+    void defaults() override;
+
+private:
+    Ui::ShowPaintEffectConfig *m_ui;
+};
+
+} // namespace KWin

effects/showpaint/showpaint_config.ui

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>ShowPaintEffectConfig</class>
+ <widget class="QWidget" name="ShowPaintEffectConfig">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>452</width>
+    <height>246</height>
+   </rect>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="KShortcutsEditor" name="shortcutsEditor" native="true">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="actionTypes">
+      <enum>KShortcutsEditor::GlobalAction</enum>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>KShortcutsEditor</class>
+   <extends>QWidget</extends>
+   <header location="global">KShortcutsEditor</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>