LibGUI: Fix re-paint issue when adding new widgets when window is alr…

…eady shown

Userland/LibGUI/Widget.cpp

@@ -36,7 +36,6 @@ void Widget::event(Event& event)
         updateLayout();
         return onResizeEvent(static_cast<ResizeEvent&>(event));
     case Event::Type::Paint: {
-        m_isDirty = false;
         PaintEvent& paintEvent = static_cast<PaintEvent&>(event);
         Painter painter(*this);
         painter.setClipRect(paintEvent.rect());
@@ -114,8 +113,10 @@ void Widget::updateLayout()
     if (!m_isVisible)
         return;
 
-    if (m_layout)
+    if (m_layout) {
         m_layout->activate();
+        update();
+    }
 }
 
 void Widget::onShowEvent(Event& event)
@@ -162,26 +163,15 @@ void Widget::setRelativeRect(const Rect& rect)
     update();
 }
 
-void Widget::setWindow(Window* window)
-{
-    m_window = window;
-    for (auto& child : m_children) {
-        if (child->isWidgetType()) {
-            Widget* childWidget = static_cast<Widget*>(child);
-            childWidget->setWindow(window);
-        }
-    }
-}
-
 bool Widget::hasFocus() const
 {
-    return m_window && m_window->focusedWidget() == this && m_window->isActive();
+    return window() && window()->focusedWidget() == this && window()->isActive();
 }
 
 void Widget::setFocus(FocusReason reason)
 {
-    ASSERT(m_window != nullptr);
-    m_window->setFocusedWidget(this, reason);
+    ASSERT(window() != nullptr);
+    window()->setFocusedWidget(this, reason);
 }
 
 bool Widget::isWidgetType() const
@@ -304,9 +294,6 @@ void Widget::update()
 
 void Widget::update(const Rect& rect)
 {
-    if (m_isDirty)
-        return;
-    m_isDirty = true;
     if (Window* widgetWindow = window()) {
         Rect widgetRelativeRect = rect;
         widgetRelativeRect.moveBy(windowRelativeRect().position());

Userland/LibGUI/Widget.h

@@ -22,9 +22,19 @@ class Widget : public CObject {
     virtual void event(Event& event) override;
     virtual bool isWidgetType() const override;
 
-    void setWindow(Window* window);
-    [[nodiscard]] Window* window() { return m_window; }
-    [[nodiscard]] const Window* window() const { return m_window; }
+    void setWindow(Window* window) { m_window = window; }
+    [[nodiscard]] Window* window()
+    {
+        if (Widget* const parent = parentWidget())
+            return parent->window();
+        return m_window;
+    }
+    [[nodiscard]] const Window* window() const
+    {
+        if (const Widget* const parent = parentWidget())
+            return parent->window();
+        return m_window;
+    }
 
     [[nodiscard]] Rect windowRelativeRect() const;
 
@@ -111,7 +121,6 @@ class Widget : public CObject {
     SizePolicy m_verticalSizePolicy { SizePolicy::Automatic };
     SizePolicy m_horizontalSizePolicy { SizePolicy::Automatic };
     bool m_isVisible { true };
-    bool m_isDirty { false };
 };
 
 } // GUI

Userland/LibGUI/Window.cpp

@@ -117,7 +117,6 @@ void Window::setCentralWidget(Widget& widget)
         return;
 
     m_centralWidget = &widget;
-    m_centralWidget->setParent(this);
     m_centralWidget->setWindow(this);
 
     Rect newRect = rect();
@@ -133,7 +132,6 @@ void Window::setCentralWidget(Widget& widget)
         newRect.setWidth(m_centralWidget->preferredSizeHint().width());
 
     resize(newRect.size());
-    m_centralWidget->resize(newRect.width(), newRect.height());
 }
 
 void Window::show()

Userland/LibGUI/WindowManager.cpp

@@ -372,13 +372,14 @@ void WindowManager::flushPainting()
         if (!bigDirtyRect.intersects(windowOuterFrameRect(window))) {
             return IteratorResult::Continue;
         }
+
+        paintWindowFrame(window);
         Bitmap* const windowBitmap = window.backBuffer();
         if (!windowBitmap) {
             std::cout << "[compose] no bitmap for window: " << window.title() << std::endl;
             return IteratorResult::Continue;
         }
 
-        paintWindowFrame(window);
         Painter painter(*m_backBuffer);
         // FIXME: Only blit pixels for updated rect
         painter.blit(window.position(), *windowBitmap);

Userland/LibGUI/main.cpp

@@ -20,11 +20,10 @@ int main()
     GUI::Widget* buttonListLayoutWidget = new GUI::Widget();
     GUI::VBoxLayout* buttonList = new GUI::VBoxLayout(buttonListLayoutWidget);
     buttonList->setSpacing(10);
-    buttonList->addWidget(*new GUI::Button("Btn1"));
-    buttonList->addWidget(*new GUI::Button("Btn2"));
-    buttonList->addWidget(*new GUI::Button("Btn3"));
-    buttonList->addWidget(*new GUI::Button("Btn4"));
-    buttonList->addWidget(*new GUI::Button("Btn5"));
+
+    static int buttonCounter = 5;
+    for (int i = 0; i < buttonCounter; ++i)
+        buttonList->addWidget(*new GUI::Button("Btn" + ADS::String::fromInt(i)));
     buttonListLayoutWidget->setLayout(buttonList);
 
     GUI::ScrollArea* scrollArea = new GUI::ScrollArea();
@@ -33,7 +32,7 @@ int main()
     GUI::Widget* rootWidget = new GUI::Widget();
     GUI::VBoxLayout* rootLayout = new GUI::VBoxLayout(rootWidget);
     GUI::Button* button = new GUI::Button(rootWidget);
-    button->setText("Resize and translate");
+    button->setText("Add to list");
     rootLayout->addWidget(*button);
     rootLayout->addWidget(*scrollArea);
     rootWidget->setLayout(rootLayout);
@@ -42,10 +41,9 @@ int main()
     win1.resize(640, 480);
     win1.setCentralWidget(*rootWidget);
     win1.setTitle("Window 1");
-    button->onClick = [&win1]() {
+    button->onClick = [buttonList]() {
         std::cout << "Button clicked" << std::endl;
-        win1.resize(720, 480);
-        win1.setPosition(100, 100);
+        buttonList->addWidget(*new GUI::Button("Btn" + ADS::String::fromInt(buttonCounter++)));
     };
     win1.show();