Bring back Window::setTransientParent, used in Carla

Signed-off-by: falkTX <falktx@falktx.com>

dgl/Window.hpp

@@ -442,6 +442,14 @@ class DISTRHO_API Window
                                 bool automaticallyScale = false,
                                 bool resizeNowIfAutoScaling = true);
 
+   /**
+      Set the transient parent of the window.
+
+      Set this for transient children like dialogs, to have them properly associated with their parent window.
+      This should be not be called for embed windows, or after making the window visible.
+    */
+    void setTransientParent(uintptr_t transientParentWindowHandle);
+
    /** DEPRECATED Use isIgnoringKeyRepeat(). */
     DISTRHO_DEPRECATED_BY("isIgnoringKeyRepeat()")
     inline bool getIgnoringKeyRepeat() const noexcept { return isIgnoringKeyRepeat(); }

dgl/src/Window.cpp

@@ -465,6 +465,11 @@ void Window::setGeometryConstraints(uint minimumWidth,
     }
 }
 
+void Window::setTransientParent(const uintptr_t transientParentWindowHandle)
+{
+    puglSetTransientParent(pData->view, transientParentWindowHandle);
+}
+
 std::vector<ClipboardDataOffer> Window::getClipboardDataOfferTypes()
 {
     std::vector<ClipboardDataOffer> offerTypes;
@@ -521,13 +526,6 @@ void Window::onFileSelected(const char*)
 }
 #endif
 
-#if 0
-void Window::setTransientWinId(const uintptr_t winId)
-{
-    puglSetTransientFor(pData->view, winId);
-}
-#endif
-
 // -----------------------------------------------------------------------
 
 END_NAMESPACE_DGL

distrho/src/DistrhoUIInternal.hpp

@@ -312,14 +312,12 @@ class UIExporter
         uiData->window->setTitle(uiTitle);
     }
 
-    void setWindowTransientWinId(const uintptr_t winId)
+    void setWindowTransientWinId(const uintptr_t transientParentWindowHandle)
     {
 #if DISTRHO_PLUGIN_HAS_EXTERNAL_UI
-        ui->setTransientWindowId(winId);
-#elif 0 /* TODO */
-        glWindow.setTransientWinId(winId);
+        ui->setTransientWindowId(transientParentWindowHandle);
 #else
-        (void)winId;
+        uiData->window->setTransientParent(transientParentWindowHandle);
 #endif
     }