democompositor: Provide an example to detect unknown apps

When a new wlShellSurface is created we can check the identity
of the client and if it is belongs to an application launched
by the democompositor. In the future such apps might be killed
and their surface not displayed.

Introduce appStateForPid to find the AppState and return it as
a QVariant to easily use it in QML. Use int as type as one can
not easily use Q_PID in QML.

Change-Id: Ibb9ac004a8016bd76f61679f5c837c99783fa7e8
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

4 files changed, 23 insertions, 0 deletions

diff --git a/wayland/democompositor/processlauncher.cpp b/wayland/democompositor/processlauncher.cpp
index c8fe15c..bb11cb9 100644
--- a/wayland/democompositor/processlauncher.cpp
+++ b/wayland/democompositor/processlauncher.cpp
@@ -74,6 +74,19 @@ WaylandProcessLauncher::~WaylandProcessLauncher()
 {
 }
 
+QVariant WaylandProcessLauncher::appStateForPid(int pid) const
+{
+    for (auto state : m_appStates) {
+        if (state.process->pid() == pid) {
+            qCDebug(procs) << "Found state for" << pid << state.appEntry.executableName;
+            return QVariant::fromValue(state);
+        }
+    }
+
+    qCDebug(procs) << "Couldn't find entry for" << pid;
+    return QVariant();
+}
+
 bool WaylandProcessLauncher::isRunning(const AppEntry& entry) const
 {
     for (auto state : m_appStates) {
diff --git a/wayland/democompositor/processlauncher.h b/wayland/democompositor/processlauncher.h
index 84f9cb8..f21be98 100644
--- a/wayland/democompositor/processlauncher.h
+++ b/wayland/democompositor/processlauncher.h
@@ -81,6 +81,7 @@ public:
     ~WaylandProcessLauncher();
     Q_INVOKABLE void launch(const AppEntry &entry);
 
+    Q_INVOKABLE QVariant appStateForPid(int pid) const;
     Q_INVOKABLE bool isRunning(const AppEntry& entry) const;
 
 Q_SIGNALS:
diff --git a/wayland/democompositor/qml/Screen.qml b/wayland/democompositor/qml/Screen.qml
index fb8d4ea..ffb8490 100644
--- a/wayland/democompositor/qml/Screen.qml
+++ b/wayland/democompositor/qml/Screen.qml
@@ -59,6 +59,7 @@ import com.theqtcompany.wlapplistmodel 1.0
 WaylandOutput {
     id: output
     property alias surfaceArea: background
+    property alias appLauncher: launcher
     property var windowList: [ ]
     property int hiddenWindowCount
 
diff --git a/wayland/democompositor/qml/main.qml b/wayland/democompositor/qml/main.qml
index 8c0c621..75d1adc 100644
--- a/wayland/democompositor/qml/main.qml
+++ b/wayland/democompositor/qml/main.qml
@@ -57,6 +57,7 @@ WaylandCompositor {
     property var primarySurfacesArea: null
 
     Screen {
+        id: mainScreen
         compositor: comp
     }
 
@@ -69,6 +70,13 @@ WaylandCompositor {
     WlShell {
         id: defaultShell
         onWlShellSurfaceCreated: {
+            const pid = shellSurface.surface.client.processId;
+            const appState = mainScreen.appLauncher.appStateForPid(pid);
+            if (!appState) {
+                console.log("shellSurface of unknown application. Continuing. PID=" + pid);
+            } else {
+                console.log("shellSurface belonging to " + appState.appEntry.executableName);
+            }
             chromeComponent.createObject(defaultOutput.surfaceArea, { "shellSurface": shellSurface } );
             defaultOutput.relayout();
         }