Merge pull request #167 from samsonwang/master

Windows raise widget example

.github/workflows/main.yml

@@ -59,7 +59,7 @@ jobs:
           cmake . ${{ matrix.additional_arguments }}
           cmake --build .
 
-      - name: Build calculator example CMake
+      - name: Build calculator example with CMake
         working-directory: examples/calculator/
         run: |
           cmake . ${{ matrix.additional_arguments }}
@@ -71,6 +71,12 @@ jobs:
           cmake . ${{ matrix.additional_arguments }}
           cmake --build .
 
+      - name: Build windows_raise_widget example with CMake
+        working-directory: examples/windows_raise_widget/
+        run: |
+          cmake . ${{ matrix.additional_arguments }}
+          cmake --build .
+
       - name: Setup MSVC environment for QMake
         uses: ilammy/msvc-dev-cmd@v1
 
@@ -80,7 +86,7 @@ jobs:
           qmake
           ${{ matrix.make }}
 
-      - name: Build calculator example QMake
+      - name: Build calculator example with QMake
         working-directory: examples/calculator/
         run: |
           qmake
@@ -91,3 +97,9 @@ jobs:
         run: |
           qmake
           ${{ matrix.make }}
+
+      - name: Build windows_raise_widget example with QMake
+        working-directory: examples/windows_raise_widget/
+        run: |
+          qmake
+          ${{ matrix.make }}

Windows.md

@@ -7,36 +7,15 @@ application can bring it's primary instance window whenever a second copy
 of the application is started.
 
 On Windows the ability to bring the application windows to the foreground is
-restricted, see [AllowSetForegroundWindow()][https://msdn.microsoft.com/en-us/library/windows/desktop/ms632668.aspx] for more
+restricted, see [AllowSetForegroundWindow()](https://msdn.microsoft.com/en-us/library/windows/desktop/ms632668.aspx) for more details.
-details.
 
 The background process (the primary instance) can bring its windows to the
 foreground if it is allowed by the current foreground process (the secondary
 instance). To bypass this `SingleApplication` must be initialized with the
-`allowSecondary` parameter set to `true` and the `options` parameter must
+`allowSecondary` parameter set to `true` .
-include `Mode::SecondaryNotification`, See `SingleApplication::Mode` for more
-details.
 
-Here is an example:
+If the widget is minimized to Windows task bar, `QWidget::raise()` or
+`QWidget::show()` can not bring it to the front, you have to use Windows API
+`ShowWindow()` .
 
-```cpp
+You can find [demo code](examples/windows_raise_widget/main.cpp) in the examples directory.
-if( app.isSecondary() ) {
-    // This API requires LIBS += User32.lib to be added to the project
-    AllowSetForegroundWindow( DWORD( app.primaryPid() ) );
-}
-
-if( app.isPrimary() ) {
-    QObject::connect(
-        &app,
-        &SingleApplication::instanceStarted,
-        this,
-        &App::instanceStarted
-    );
-}
-```
-
-```cpp
-void App::instanceStarted() {
-    QApplication::setActiveWindow( [window/widget to set to the foreground] );
-}
-```

examples/windows_raise_widget/CMakeLists.txt

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.7.0)
+
+project(windows_raise_widget LANGUAGES CXX)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_WIN32_EXECUTABLE TRUE)
+
+# SingleApplication base class
+set(QAPPLICATION_CLASS QApplication)
+add_subdirectory(../.. SingleApplication)
+
+find_package(Qt${QT_DEFAULT_MAJOR_VERSION} COMPONENTS Core Widgets REQUIRED)
+
+add_executable(${PROJECT_NAME} main.cpp)
+
+target_link_libraries(${PROJECT_NAME} SingleApplication::SingleApplication)

examples/windows_raise_widget/main.cpp

@@ -0,0 +1,59 @@
+
+#include <QWidget>
+
+#include "singleapplication.h"
+
+#ifdef Q_OS_WINDOWS
+#include <Windows.h>
+#endif
+
+void raiseWidget(QWidget* widget);
+
+int main(int argc, char *argv[]) {
+
+#ifdef Q_OS_WINDOWS
+    SingleApplication app(argc, argv, true);
+
+    if (app.isSecondary()) {
+
+        AllowSetForegroundWindow( DWORD( app.primaryPid() ) );
+
+        app.sendMessage("RAISE_WIDGET");
+
+        return 0;
+    }
+#else
+    SingleApplication app(argc, argv);
+#endif
+
+    QWidget* widget = new QWidget;
+
+#ifdef Q_OS_WINDOWS
+    QObject::connect(&app, &SingleApplication::receivedMessage,
+                     widget, [widget] () { raiseWidget(widget); } );
+#else
+    QObject::connect(&app, &SingleApplication::instanceStarted,
+                     widget, [widget] () { raiseWidget(widget); } );
+#endif
+
+    widget->show();
+
+    return app.exec();
+}
+
+void raiseWidget(QWidget* widget) {
+#ifdef Q_OS_WINDOWS
+    HWND hwnd = (HWND)widget->winId();
+
+    // check if widget is minimized to Windows task bar
+    if (::IsIconic(hwnd)) {
+        ::ShowWindow(hwnd, SW_RESTORE);
+    }
+
+    ::SetForegroundWindow(hwnd);
+#else
+    widget->show();
+    widget->raise();
+    widget->activateWindow();
+#endif
+}

examples/windows_raise_widget/windows_raise_widget.pro

@@ -0,0 +1,10 @@
+# Single Application implementation
+include(../../singleapplication.pri)
+DEFINES += QAPPLICATION_CLASS=QApplication
+
+QT += widgets
+SOURCES += main.cpp
+
+win32{
+  LIBS += User32.lib
+}