GWindow: Add SerenityKeys minimum functionality

Author: https://github.com/faissaloo
Commit: https://github.com/SerenityOS/serenity/commit/72264661fdc
Pull-request: https://github.com/SerenityOS/serenity/pull/173
Reviewed-by: https://github.com/awesomekling

Applications/About/main.cpp

@@ -4,6 +4,7 @@
 #include <LibGUI/GButton.h>
 #include <LibGUI/GBoxLayout.h>
 #include <LibGUI/GDesktop.h>
+#include <stdio.h>
 #include <sys/utsname.h>
 
 int main(int argc, char** argv)

LibGUI/GAbstractButton.h

@@ -26,6 +26,7 @@ public:
     virtual void click() = 0;
     virtual const char* class_name() const override { return "GAbstractButton"; }
     virtual bool accepts_focus() const override { return true; }
+    virtual bool accepts_keyboard_select() const { return true; }
 
 protected:
     explicit GAbstractButton(GWidget* parent);

LibGUI/GButton.cpp

@@ -64,6 +64,10 @@ void GButton::click()
         on_click(*this);
 }
 
+/*bool GButton::accepts_keyboard_select() const {
+  return is_enabled();
+}*/
+
 void GButton::set_action(GAction& action)
 {
     m_action = action.make_weak_ptr();

LibGUI/GWidget.h

@@ -106,6 +106,7 @@ public:
     void update(const Rect&);
 
     virtual bool accepts_focus() const { return false; }
+    virtual bool accepts_keyboard_select() const { return false; }
 
     bool is_focused() const;
     void set_focus(bool);

LibGUI/GWindow.cpp

@@ -230,6 +230,19 @@ void GWindow::event(CEvent& event)
         for (auto& rect : rects)
             m_main_widget->event(*make<GPaintEvent>(rect));
 
+        if (m_keybind_mode) {
+          //If we're in keybind mode indicate widgets in m_potential_keybind_widgets
+          GPainter painter(*m_main_widget);
+          painter.draw_text(Rect(20,20,20,20), m_entered_keybind.characters(), TextAlignment::TopLeft, Color::Green);
+
+          for (auto& keypair: m_hashed_potential_keybind_widgets) {
+            auto widget = keypair.value;
+            auto rect = Rect(widget->x()-5, widget->y()-5, 12, 12);
+            painter.draw_text(rect, keypair.key.characters(), TextAlignment::TopLeft, Color::Black);
+          }
+
+        }
+
         if (m_double_buffering_enabled)
             flip(rects);
         else if (created_new_backing_store)
@@ -251,10 +264,44 @@ void GWindow::event(CEvent& event)
     }
 
     if (event.type() == GEvent::KeyUp || event.type() == GEvent::KeyDown) {
-        if (m_focused_widget)
-            return m_focused_widget->event(event);
-        if (m_main_widget)
-            return m_main_widget->event(event);
+        auto keyevent = static_cast<GKeyEvent&>(event);
+        if (keyevent.logo() && event.type() == GEvent::KeyUp) {
+            if (m_keybind_mode) {
+                m_keybind_mode = false;
+            } else {
+                m_keybind_mode = true;
+                find_keyboard_selectable();
+                m_entered_keybind = "";
+            }
+            update();
+            return;
+        }
+
+        if (m_keybind_mode) {
+            StringBuilder builder;
+            //Y u no work
+            builder.append(m_entered_keybind);
+            builder.append(keyevent.text());
+            m_entered_keybind = builder.to_string();
+
+            auto found_widget = m_hashed_potential_keybind_widgets.find(m_entered_keybind);
+            if (found_widget != m_hashed_potential_keybind_widgets.end()) {
+              m_keybind_mode = false;
+              const auto& point = Point();
+              auto event = make<GMouseEvent>(GEvent::MouseDown, point, 0, GMouseButton::Left, 0, 0);
+              found_widget->value->event(*event);
+              event = make<GMouseEvent>(GEvent::MouseUp, point, 0, GMouseButton::Left, 0, 0);
+              found_widget->value->event(*event);
+              //Call click on the found widget
+            }
+            //m_entered_keybind.append(keyevent.text());
+            update();
+        } else {
+            if (m_focused_widget)
+              return m_focused_widget->event(event);
+            if (m_main_widget)
+              return m_main_widget->event(event);
+        }
         return;
     }
 
@@ -296,6 +343,44 @@ void GWindow::event(CEvent& event)
     CObject::event(event);
 }
 
+void GWindow::find_keyboard_selectable() {
+    m_potential_keybind_widgets.clear();
+    m_hashed_potential_keybind_widgets.clear();
+    find_keyboard_selectable_children(m_main_widget);
+
+    size_t buffer_length = ceil_div(m_potential_keybind_widgets.size(), ('z'-'a'))+1;
+    char keybind_buffer[buffer_length];
+    for (size_t i = 0; i < buffer_length-1; i++) {
+      keybind_buffer[i] = 'a';
+    }
+    keybind_buffer[buffer_length-1] = '\0';
+
+    for (auto& widget: m_potential_keybind_widgets) {
+      m_hashed_potential_keybind_widgets.set(String(keybind_buffer), widget);
+
+      for (size_t i = 0; i < buffer_length-1; i++) {
+        if (keybind_buffer[i] >= 'z') {
+          keybind_buffer[i] = 'a';
+        } else {
+          keybind_buffer[i]++;
+          break;
+        }
+      }
+    }
+}
+
+void GWindow::find_keyboard_selectable_children(GWidget* widget) {
+  //Rather than painting immediately we need a step to collect all the keybinds first
+  widget -> for_each_child_widget([&] (auto& child) {
+      if (child.accepts_keyboard_select()) {
+        //auto rect = Rect(child.x()-5, child.y()-5, 10, 10);
+        m_potential_keybind_widgets.append(&child);
+        find_keyboard_selectable_children(&child);
+      }
+      return IterationDecision::Continue;
+  });
+}
+
 bool GWindow::is_visible() const
 {
     return false;
@@ -305,6 +390,10 @@ void GWindow::update(const Rect& a_rect)
 {
     if (!m_window_id)
         return;
+
+    //We probably shouldn't clear the buffer on updates
+    //find_keyboard_selectable();
+
     for (auto& pending_rect : m_pending_paint_event_rects) {
         if (pending_rect.contains(a_rect)) {
 #ifdef UPDATE_COALESCING_DEBUG

LibGUI/GWindow.h

@@ -1,12 +1,15 @@
 #pragma once
 
 #include <AK/AKString.h>
+#include <AK/HashMap.h>
+#include <AK/StringBuilder.h>
 #include <AK/WeakPtr.h>
 #include <LibCore/CObject.h>
 #include <LibGUI/GWindowType.h>
 #include <SharedGraphics/GraphicsBitmap.h>
 #include <SharedGraphics/Rect.h>
 
+class GPainter;
 class GWidget;
 class GWMEvent;
 
@@ -130,6 +133,8 @@ protected:
 private:
     virtual bool is_window() const override final { return true; }
 
+    void find_keyboard_selectable();
+    void find_keyboard_selectable_children(GWidget* widget);
     Retained<GraphicsBitmap> create_backing_bitmap(const Size&);
     void set_current_backing_bitmap(GraphicsBitmap&, bool flush_immediately = false);
     void flip(const Vector<Rect, 32>& dirty_rects);
@@ -159,4 +164,8 @@ private:
     bool m_resizable { true };
     bool m_fullscreen { false };
     bool m_show_titlebar { true };
+    bool m_keybind_mode { false };
+    String m_entered_keybind;
+    Vector<GWidget*> m_potential_keybind_widgets;
+    HashMap<String, GWidget*> m_hashed_potential_keybind_widgets;
 };