Implement window activate function

README.md

@@ -63,6 +63,14 @@ defos.minimize()
 
 ---
 
+**Activate (focus) window**. Not supported on HTML5.
+
+```lua
+defos.activate()
+```
+
+---
+
 **Get/set the window's size and position** in screen coordinates. The window area
 includes the title bar, so the actual contained game view area might be smaller
 than the given metrics.

defos/src/defos.cpp

@@ -171,6 +171,12 @@ static int minimize(lua_State *L)
     return 0;
 }
 
+static int activate(lua_State *L)
+{
+    defos_activate();
+    return 0;
+}
+
 static int set_window_icon(lua_State *L)
 {
     const char *icon_path = luaL_checkstring(L, 1);
@@ -615,6 +621,7 @@ static const luaL_reg Module_methods[] =
         {"set_maximized", set_maximized},
         {"is_maximized", is_maximized},
         {"minimize", minimize},
+        {"activate", activate},
         {"set_console_visible", set_console_visible},
         {"is_console_visible", is_console_visible},
         {"set_cursor_visible", set_cursor_visible},

defos/src/defos_html5.cpp

@@ -131,6 +131,10 @@ void defos_minimize() {
     dmLogWarning("Method 'minimize' is not supported in HTML5");
 }
 
+void defos_activate() {
+    dmLogWarning("Method 'activate' is not supported in HTML5");
+}
+
 void defos_toggle_fullscreen() {
     EM_ASM(Module.toggleFullscreen(););
 }

defos/src/defos_linux.cpp

@@ -328,6 +328,19 @@ void defos_minimize()
     XIconifyWindow(disp, win, screen);
 }
 
+void defos_activate()
+{
+    send_message(win,
+        _NET_ACTIVE_WINDOW,
+        1,
+        1,
+        0,
+        0,
+        0
+    );
+    XFlush(disp);
+}
+
 void defos_set_console_visible(bool visible)
 {
     dmLogWarning("Method 'set_console_visible' is only supported on Windows");

defos/src/defos_mac.mm

@@ -132,6 +132,10 @@ void defos_minimize() {
     [window performMiniaturize: nil];
 }
 
+void defos_activate() {
+    [[NSApplication sharedApplication] activateIgnoringOtherApps: YES];
+}
+
 void defos_set_window_title(const char* title_lua) {
     NSString* title = [NSString stringWithUTF8String:title_lua];
     [window setTitle:title];

defos/src/defos_private.h

@@ -80,6 +80,7 @@ extern bool defos_is_fullscreen();
 extern bool defos_is_maximized();
 extern bool defos_is_always_on_top();
 extern void defos_minimize();
+extern void defos_activate();
 
 extern void defos_set_window_title(const char* title_lua);
 extern void  defos_set_window_icon(const char *icon_path);

defos/src/defos_win.cpp

@@ -188,6 +188,12 @@ void defos_minimize()
     ShowWindow(window, SW_MINIMIZE);
 }
 
+void defos_activate()
+{
+    HWND window = dmGraphics::GetNativeWindowsHWND();
+    SetForegroundWindow(window);
+}
+
 void defos_set_console_visible(bool visible)
 {
     ::ShowWindow(::GetConsoleWindow(), visible ? SW_SHOW : SW_HIDE);