CMake:Android: add property QT_ANDROID_APP_ICON to set app icon

This allows users to set an app icon directly from CMake
without needing to manage a custom AndroidManifest.xml file.

Fixes: QTBUG-92013
Change-Id: Ic2f44978697d0f4833bde7f66630943d3032e982
Reviewed-by:  Alexey Edelev <alexey.edelev@qt.io>

src/android/templates/AndroidManifest.xml

@@ -15,6 +15,7 @@
         android:name="org.qtproject.qt.android.bindings.QtApplication"
         android:hardwareAccelerated="true"
         android:label="-- %%INSERT_APP_NAME%% --"
+        android:icon="-- %%INSERT_APP_ICON%% --"
         android:requestLegacyExternalStorage="true"
         android:allowBackup="true"
         android:fullBackupOnly="false">

src/android/templates/doc/src/android-manifest-file-configuration.qdoc

@@ -70,7 +70,7 @@ Qt sets the following manifest configuration by default:
         default values are \c anyDensity, \c largeScreens,
         \c normalScreens, and \c smallScreens.
 \row
-    \li {1, 6} \l {Android: App Manifest <application>}{<application>}
+    \li {1, 7} \l {Android: App Manifest <application>}{<application>}
     \li android:name
     \li The application class name. Default value is
         \c {org.qtproject.qt.android.bindings.QtApplication}.
@@ -78,6 +78,11 @@ Qt sets the following manifest configuration by default:
     \li android:label
     \li The application name label. Default value is the Qt project's target name.
         This can be set using \l {QT_ANDROID_APP_NAME}.
+\row
+    \li android:icon
+    \li The application icon as a reference to a drawable or mipmap resource. This
+        tag is not used unless set using \l {QT_ANDROID_APP_ICON} or set manually
+        in the \c {AndroidManifest.xml}.
 \row
     \li android:hardwareAccelerated
     \li Sets hardware acceleration preference. The default value is \c true.

src/corelib/Qt6AndroidMacros.cmake

@@ -225,6 +225,10 @@ function(qt6_android_generate_deployment_settings target)
     _qt_internal_add_android_deployment_property(file_contents "android-app-name"
         ${target} "QT_ANDROID_APP_NAME")
 
+    # app icon
+    _qt_internal_add_android_deployment_property(file_contents "android-app-icon"
+        ${target} "QT_ANDROID_APP_ICON")
+
     # version code
     _qt_internal_add_android_deployment_property(file_contents "android-version-code"
         ${target} "QT_ANDROID_VERSION_CODE")

src/corelib/doc/src/cmake/cmake-properties.qdoc

@@ -328,6 +328,51 @@ set_target_properties(${target} PROPERTIES
 \sa {QT_ANDROID_PACKAGE_NAME}
 */
 
+/*!
+\page cmake-target-property-qt-android-app-icon.html
+\ingroup cmake-properties-qtcore
+\ingroup cmake-target-properties-qtcore
+
+\title QT_ANDROID_APP_ICON
+\target cmake-target-property-QT_ANDROID_APP_ICON
+\ingroup cmake-android-manifest-properties
+
+\summary {The Android app's icon resource name.}
+
+\cmakepropertysince 6.9
+\cmakepropertyandroidonly
+
+Specifies the app's icon name as an Android drawable or mipmap reference.
+This only works if the \c {AndroidManifest.xml} file contains the placeholder
+or when the \c {AndroidManifest.xml} is managed by Qt.
+
+\badcode
+<application
+    ...
+    android:icon="-- %%INSERT_APP_ICON%% --"
+    ...
+>
+\endcode
+
+You can use this property as follows:
+
+\badcode
+set_target_properties(${target} PROPERTIES
+    QT_ANDROID_APP_ICON "@mipmap/ic_launcher"
+)
+\endcode
+
+Or using drawables:
+
+\badcode
+set_target_properties(${target} PROPERTIES
+    QT_ANDROID_APP_ICON "@drawable/ic_launcher"
+)
+\endcode
+
+\sa{qt6_android_generate_deployment_settings}{qt_android_generate_deployment_settings()}
+*/
+
 /*!
 \page cmake-target-property-qt-android-version-code.html
 \ingroup cmake-properties-qtcore

src/corelib/doc/src/cmake/qt_android_generate_deployment_settings.qdoc

@@ -65,6 +65,7 @@ how to accomplish this.
 \li \l{cmake-target-property-QT_ANDROID_TARGET_SDK_VERSION}{QT_ANDROID_TARGET_SDK_VERSION}
 \li \l{cmake-target-property-QT_ANDROID_PACKAGE_NAME}{QT_ANDROID_PACKAGE_NAME}
 \li \l{cmake-target-property-QT_ANDROID_APP_NAME}{QT_ANDROID_APP_NAME}
+\li \l{cmake-target-property-QT_ANDROID_APP_ICON}{QT_ANDROID_APP_ICON}
 \li \l{cmake-target-property-QT_ANDROID_VERSION_NAME}{QT_ANDROID_VERSION_NAME}
 \li \l{cmake-target-property-QT_ANDROID_VERSION_CODE}{QT_ANDROID_VERSION_CODE}
 \li \l{cmake-target-property-QT_QML_IMPORT_PATH}{QT_QML_IMPORT_PATH}

src/tools/androiddeployqt/main.cpp

@@ -192,6 +192,7 @@ struct Options
     QString systemLibsPath;
     QString packageName;
     QString appName;
+    QString appIcon;
     QStringList extraLibs;
     QHash<QString, QStringList> archExtraLibs;
     QStringList extraPlugins;
@@ -1380,6 +1381,12 @@ bool readInputFile(Options *options)
             options->appName = options->applicationBinary;
     }
 
+    {
+        const QJsonValue androidAppIcon = jsonObject.value("android-app-icon"_L1);
+        if (!androidAppIcon.isUndefined())
+            options->appIcon = androidAppIcon.toString();
+    }
+
     {
         using ItFlag = QDirListing::IteratorFlag;
         const QJsonValue deploymentDependencies = jsonObject.value("deployment-dependencies"_L1);
@@ -1701,6 +1708,11 @@ bool updateFile(const QString &fileName, const QHash<QString, QString> &replacem
             return false;
         }
 
+        // Remove leftover empty lines after replacements, for example,
+        // in case of setting the app icon.
+        QRegularExpression emptyLinesRegex("\\n\\s+\\n"_L1);
+        contents = QString::fromUtf8(contents).replace(emptyLinesRegex, "\n"_L1).toUtf8();
+
         inputFile.write(contents);
     }
 
@@ -1859,6 +1871,10 @@ bool updateAndroidManifest(Options &options)
     replacements[QStringLiteral("-- %%INSERT_VERSION_CODE%% --")] = options.versionCode;
     replacements[QStringLiteral("package=\"org.qtproject.example\"")] = "package=\"%1\""_L1.arg(options.packageName);
 
+    const QString iconAttribute = "android:icon=\"%1\""_L1;
+    replacements[iconAttribute.arg("-- %%INSERT_APP_ICON%% --"_L1)] = options.appIcon.isEmpty() ?
+            ""_L1 : iconAttribute.arg(options.appIcon);
+
     const QString androidManifestPath = options.outputDirectory + "/AndroidManifest.xml"_L1;
     QFile androidManifestXml(androidManifestPath);
     // User may have manually defined permissions in the AndroidManifest.xml