WindowServer: Make WSButton behave more like a normal button.

Previously it would just close the window on MouseDown. Now we do the normal
thing where we require a MouseUp inside the button rect before committing.

Servers/WindowServer/WSButton.cpp

@@ -1,11 +1,13 @@
 #include <WindowServer/WSButton.h>
 #include <WindowServer/WSMessage.h>
+#include <WindowServer/WSWindowManager.h>
 #include <SharedGraphics/Painter.h>
 #include <SharedGraphics/StylePainter.h>
 #include <SharedGraphics/CharacterBitmap.h>
 
-WSButton::WSButton(Retained<CharacterBitmap>&& bitmap, Function<void()>&& on_click_handler)
+WSButton::WSButton(WSWindowFrame& frame, Retained<CharacterBitmap>&& bitmap, Function<void()>&& on_click_handler)
     : on_click(move(on_click_handler))
+    , m_frame(frame)
     , m_bitmap(move(bitmap))
 {
 }
@@ -21,13 +23,43 @@ void WSButton::paint(Painter& painter)
     StylePainter::paint_button(painter, rect(), ButtonStyle::Normal, m_pressed);
     auto x_location = rect().center();
     x_location.move_by(-(m_bitmap->width() / 2), -(m_bitmap->height() / 2));
+    if (m_pressed)
+        x_location.move_by(1, 1);
     painter.draw_bitmap(x_location, *m_bitmap, Color::Black);
 }
 
 void WSButton::on_mouse_event(const WSMouseEvent& event)
 {
-    if (event.type() == WSMessage::MouseDown) {
-        if (on_click)
-            on_click();
+    auto& wm = WSWindowManager::the();
+
+    if (event.type() == WSMessage::MouseDown && event.button() == MouseButton::Left) {
+        m_pressed = true;
+        wm.set_cursor_tracking_button(this);
+        wm.invalidate(screen_rect());
+        return;
+    }
+
+    if (event.type() == WSMessage::MouseMove) {
+        bool old_pressed = m_pressed;
+        m_pressed = rect().contains(event.position());
+        if (old_pressed != m_pressed)
+            wm.invalidate(screen_rect());
+    }
+
+    if (event.type() == WSMessage::MouseUp && event.button() == MouseButton::Left) {
+        WSWindowManager::the().set_cursor_tracking_button(nullptr);
+        bool old_pressed = m_pressed;
+        m_pressed = false;
+        if (rect().contains(event.position())) {
+            if (on_click)
+                on_click();
+        }
+        if (old_pressed != m_pressed)
+            wm.invalidate(screen_rect());
     }
 }
+
+Rect WSButton::screen_rect() const
+{
+    return m_relative_rect.translated(m_frame.rect().location());
+}

Servers/WindowServer/WSButton.h

@@ -7,16 +7,18 @@
 class CharacterBitmap;
 class Painter;
 class WSMouseEvent;
+class WSWindowFrame;
 
-class WSButton {
+class WSButton final {
 public:
-    WSButton(Retained<CharacterBitmap>&&, Function<void()>&& on_click_handler);
+    WSButton(WSWindowFrame&, Retained<CharacterBitmap>&&, Function<void()>&& on_click_handler);
     ~WSButton();
 
     Rect relative_rect() const { return m_relative_rect; }
     void set_relative_rect(const Rect& rect) { m_relative_rect = rect; }
 
     Rect rect() const { return { { }, m_relative_rect.size() }; }
+    Rect screen_rect() const;
 
     void paint(Painter&);
 
@@ -27,6 +29,7 @@ public:
     bool is_visible() const { return m_visible; }
 
 private:
+    WSWindowFrame& m_frame;
     Rect m_relative_rect;
     Retained<CharacterBitmap> m_bitmap;
     bool m_pressed { false };

Servers/WindowServer/WSWindowFrame.cpp

@@ -32,7 +32,7 @@ WSWindowFrame::WSWindowFrame(WSWindow& window)
     if (!s_close_button_bitmap)
         s_close_button_bitmap = &CharacterBitmap::create_from_ascii(s_close_button_bitmap_data, s_close_button_bitmap_width, s_close_button_bitmap_height).leak_ref();
 
-    m_buttons.append(make<WSButton>(*s_close_button_bitmap, [this] {
+    m_buttons.append(make<WSButton>(*this, *s_close_button_bitmap, [this] {
         m_window.on_message(WSMessage(WSMessage::WindowCloseRequest));
     }));
 }
@@ -181,6 +181,11 @@ Rect WSWindowFrame::rect() const
     return frame_rect_for_window_type(m_window.type(), m_window.rect());
 }
 
+void WSWindowFrame::invalidate_title_bar()
+{
+    WSWindowManager::the().invalidate(title_bar_rect().translated(rect().location()));
+}
+
 void WSWindowFrame::notify_window_rect_changed(const Rect& old_rect, const Rect& new_rect)
 {
     int window_button_width = 15;

Servers/WindowServer/WSWindowFrame.h

@@ -17,6 +17,7 @@ public:
     void paint(Painter&);
     void on_mouse_event(const WSMouseEvent&);
     void notify_window_rect_changed(const Rect& old_rect, const Rect& new_rect);
+    void invalidate_title_bar();
 
 private:
     Rect title_bar_rect() const;

Servers/WindowServer/WSWindowManager.cpp

@@ -16,7 +16,8 @@
 #include <time.h>
 #include <SharedGraphics/StylePainter.h>
 #include <SharedGraphics/PNGLoader.h>
-#include "WSCursor.h"
+#include <WindowServer/WSCursor.h>
+#include <WindowServer/WSButton.h>
 
 //#define DEBUG_COUNTERS
 //#define RESIZE_DEBUG
@@ -614,6 +615,9 @@ void WSWindowManager::process_mouse_event(const WSMouseEvent& event, WSWindow*&
     if (process_ongoing_window_resize(event, event_window))
         return;
 
+    if (m_cursor_tracking_button)
+        return m_cursor_tracking_button->on_mouse_event(event.translated(-m_cursor_tracking_button->screen_rect().location()));
+
     HashTable<WSWindow*> windows_who_received_mouse_event_due_to_cursor_tracking;
 
     for (auto* window = m_windows_in_order.tail(); window; window = window->prev()) {

Servers/WindowServer/WSWindowManager.h

@@ -25,6 +25,7 @@ class WSWindow;
 class WSClientConnection;
 class WSWindowSwitcher;
 class GraphicsBitmap;
+class WSButton;
 
 enum class ResizeDirection { None, Left, UpLeft, Up, UpRight, Right, DownRight, Down, DownLeft };
 
@@ -98,6 +99,7 @@ public:
     const WSCursor& move_cursor() const { return *m_move_cursor; }
 
     void set_active_window(WSWindow*);
+    void set_cursor_tracking_button(WSButton* button) { m_cursor_tracking_button = button; }
 
 private:
     void process_mouse_event(const WSMouseEvent&, WSWindow*& event_window);
@@ -202,6 +204,7 @@ private:
     CircularQueue<float, 30> m_cpu_history;
 
     String m_username;
+    WSButton* m_cursor_tracking_button { nullptr };
 };
 
 template<typename Callback>