LibGUI+WindowServer: Add app-global keyboard shortcuts.

This patch adds a GShortcut class. Each GAction can have a GShortcut which
will cause the event loop to listen for that key combination app-globally
and activate the event in case it's pressed.

The shortcut will also be displayed when the action is added to a menu.

Use this to hook up Alt+Up with the "open parent directory" action in the
FileManager app. :^)

8 files changed, 237 insertions, 8 deletions

diff --git a/LibGUI/GAction.cpp b/LibGUI/GAction.cpp
index aa6e52c5df..27321c2ff4 100644
--- a/LibGUI/GAction.cpp
+++ b/LibGUI/GAction.cpp
@@ -1,4 +1,5 @@
 #include <LibGUI/GAction.h>
+#include <LibGUI/GEventLoop.h>
 
 GAction::GAction(const String& text, const String& custom_data, Function<void(const GAction&)> on_activation_callback)
     : on_activation(move(on_activation_callback))
@@ -19,8 +20,19 @@ GAction::GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<
 {
 }
 
+GAction::GAction(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> on_activation_callback)
+    : on_activation(move(on_activation_callback))
+    , m_text(text)
+    , m_icon(move(icon))
+    , m_shortcut(shortcut)
+{
+    GEventLoop::register_action_with_shortcut(Badge<GAction>(), *this);
+}
+
 GAction::~GAction()
 {
+    if (m_shortcut.is_valid())
+        GEventLoop::unregister_action_with_shortcut(Badge<GAction>(), *this);
 }
 
 void GAction::activate()
diff --git a/LibGUI/GAction.h b/LibGUI/GAction.h
index 305abc59e3..959995d38b 100644
--- a/LibGUI/GAction.h
+++ b/LibGUI/GAction.h
@@ -5,6 +5,7 @@
 #include <AK/Retainable.h>
 #include <AK/Retained.h>
 #include <SharedGraphics/GraphicsBitmap.h>
+#include <LibGUI/GShortcut.h>
 
 class GAction : public Retainable<GAction> {
 public:
@@ -20,9 +21,14 @@ public:
     {
         return adopt(*new GAction(text, move(icon), move(callback)));
     }
+    static Retained<GAction> create(const String& text, const GShortcut& shortcut, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> callback)
+    {
+        return adopt(*new GAction(text, shortcut, move(icon), move(callback)));
+    }
     ~GAction();
 
     String text() const { return m_text; }
+    GShortcut shortcut() const { return m_shortcut; }
     String custom_data() const { return m_custom_data; }
     const GraphicsBitmap* icon() const { return m_icon.ptr(); }
 
@@ -32,11 +38,13 @@ public:
 
 private:
     GAction(const String& text, Function<void(const GAction&)> = nullptr);
+    GAction(const String& text, const GShortcut&, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr);
     GAction(const String& text, RetainPtr<GraphicsBitmap>&& icon, Function<void(const GAction&)> = nullptr);
     GAction(const String& text, const String& custom_data = String(), Function<void(const GAction&)> = nullptr);
 
     String m_text;
     String m_custom_data;
     RetainPtr<GraphicsBitmap> m_icon;
+    GShortcut m_shortcut;
 };
 
diff --git a/LibGUI/GEventLoop.cpp b/LibGUI/GEventLoop.cpp
index c8aa0b2bf1..7e671e7ab7 100644
--- a/LibGUI/GEventLoop.cpp
+++ b/LibGUI/GEventLoop.cpp
@@ -18,18 +18,17 @@
 
 //#define GEVENTLOOP_DEBUG
 
+static HashMap<GShortcut, GAction*>* g_actions;
 static GEventLoop* s_mainGEventLoop;
 
-void GEventLoop::initialize()
-{
-    s_mainGEventLoop = nullptr;
-}
-
 GEventLoop::GEventLoop()
 {
     if (!s_mainGEventLoop)
         s_mainGEventLoop = this;
 
+    if (!g_actions)
+        g_actions = new HashMap<GShortcut, GAction*>;
+
     m_event_fd = socket(AF_LOCAL, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
     if (m_event_fd < 0) {
         perror("socket");
@@ -154,6 +153,14 @@ void GEventLoop::handle_key_event(const WSAPI_ServerMessage& event, GWindow& win
 #ifdef GEVENTLOOP_DEBUG
     dbgprintf("WID=%x KeyEvent character=0x%b\n", event.window_id, event.key.character);
 #endif
+
+    unsigned modifiers = (event.key.alt * Mod_Alt) + (event.key.ctrl * Mod_Ctrl) + (event.key.shift * Mod_Shift);
+    auto it = g_actions->find(GShortcut(modifiers, (KeyCode)event.key.key));
+    if (it != g_actions->end()) {
+        (*it).value->activate();
+        return;
+    }
+
     auto key_event = make<GKeyEvent>(event.type == WSAPI_ServerMessage::Type::KeyDown ? GEvent::KeyDown : GEvent::KeyUp, event.key.key);
     key_event->m_alt = event.key.alt;
     key_event->m_ctrl = event.key.ctrl;
@@ -448,3 +455,13 @@ WSAPI_ServerMessage GEventLoop::sync_request(const WSAPI_ClientMessage& request,
     ASSERT(success);
     return response;
 }
+
+void GEventLoop::register_action_with_shortcut(Badge<GAction>, GAction& action)
+{
+    g_actions->set(action.shortcut(), &action);
+}
+
+void GEventLoop::unregister_action_with_shortcut(Badge<GAction>, GAction& action)
+{
+    g_actions->remove(action.shortcut());
+}
diff --git a/LibGUI/GEventLoop.h b/LibGUI/GEventLoop.h
index 152c8b52f9..ab79a5ba4b 100644
--- a/LibGUI/GEventLoop.h
+++ b/LibGUI/GEventLoop.h
@@ -1,13 +1,14 @@
 #pragma once
 
-#include "GEvent.h"
 #include <AK/Badge.h>
 #include <AK/HashMap.h>
 #include <AK/OwnPtr.h>
 #include <AK/Vector.h>
 #include <AK/WeakPtr.h>
 #include <WindowServer/WSAPITypes.h>
+#include <LibGUI/GEvent.h>
 
+class GAction;
 class GObject;
 class GNotifier;
 class GWindow;
@@ -23,8 +24,6 @@ public:
 
     static GEventLoop& main();
 
-    static void initialize();
-
     bool running() const { return m_running; }
 
     int register_timer(GObject&, int milliseconds, bool should_reload);
@@ -42,6 +41,9 @@ public:
 
     pid_t server_pid() const { return m_server_pid; }
 
+    static void register_action_with_shortcut(Badge<GAction>, GAction&);
+    static void unregister_action_with_shortcut(Badge<GAction>, GAction&);
+
 private:
     void wait_for_event();
     bool drain_messages_from_server();
diff --git a/LibGUI/GMenu.cpp b/LibGUI/GMenu.cpp
index cb5ae39c1e..91a22655f9 100644
--- a/LibGUI/GMenu.cpp
+++ b/LibGUI/GMenu.cpp
@@ -68,6 +68,16 @@ int GMenu::realize_menu()
             ASSERT(action.text().length() < (ssize_t)sizeof(request.text));
             strcpy(request.text, action.text().characters());
             request.text_length = action.text().length();
+
+            if (action.shortcut().is_valid()) {
+                auto shortcut_text = action.shortcut().to_string();
+                ASSERT(shortcut_text.length() < (ssize_t)sizeof(request.menu.shortcut_text));
+                strcpy(request.menu.shortcut_text, shortcut_text.characters());
+                request.menu.shortcut_text_length = shortcut_text.length();
+            } else {
+                request.menu.shortcut_text_length = 0;
+            }
+
             GEventLoop::main().sync_request(request, WSAPI_ServerMessage::Type::DidAddMenuItem);
         }
     }
diff --git a/LibGUI/GShortcut.cpp b/LibGUI/GShortcut.cpp
new file mode 100644
index 0000000000..7673133820
--- /dev/null
+++ b/LibGUI/GShortcut.cpp
@@ -0,0 +1,137 @@
+#include <LibGUI/GShortcut.h>
+#include <AK/StringBuilder.h>
+
+static String to_string(KeyCode key)
+{
+    switch (key) {
+    case Key_Escape: return "Escape";
+    case Key_Tab: return "Tab";
+    case Key_Backspace: return "Backspace";
+    case Key_Return: return "Return";
+    case Key_Insert: return "Insert";
+    case Key_Delete: return "Delete";
+    case Key_PrintScreen: return "PrintScreen";
+    case Key_SysRq: return "SysRq";
+    case Key_Home: return "Home";
+    case Key_End: return "End";
+    case Key_Left: return "Left";
+    case Key_Up: return "Up";
+    case Key_Right: return "Right";
+    case Key_Down: return "Down";
+    case Key_PageUp: return "PageUp";
+    case Key_PageDown: return "PageDown";
+    case Key_Shift: return "Shift";
+    case Key_Control: return "Control";
+    case Key_Alt: return "Alt";
+    case Key_CapsLock: return "CapsLock";
+    case Key_NumLock: return "NumLock";
+    case Key_ScrollLock: return "ScrollLock";
+    case Key_F1: return "F1";
+    case Key_F2: return "F2";
+    case Key_F3: return "F3";
+    case Key_F4: return "F4";
+    case Key_F5: return "F5";
+    case Key_F6: return "F6";
+    case Key_F7: return "F7";
+    case Key_F8: return "F8";
+    case Key_F9: return "F9";
+    case Key_F10: return "F10";
+    case Key_F11: return "F11";
+    case Key_F12: return "F12";
+    case Key_Space: return "Space";
+    case Key_ExclamationPoint: return "!";
+    case Key_DoubleQuote: return "\"";
+    case Key_Hashtag: return "#";
+    case Key_Dollar: return "$";
+    case Key_Percent: return "%";
+    case Key_Ampersand: return "&";
+    case Key_Apostrophe: return "'";
+    case Key_LeftParen: return "(";
+    case Key_RightParen: return ")";
+    case Key_Asterisk: return "*";
+    case Key_Plus: return "+";
+    case Key_Comma: return ",";
+    case Key_Minus: return "-";
+    case Key_Period: return ",";
+    case Key_Slash: return "/";
+    case Key_0: return "0";
+    case Key_1: return "1";
+    case Key_2: return "2";
+    case Key_3: return "3";
+    case Key_4: return "4";
+    case Key_5: return "5";
+    case Key_6: return "6";
+    case Key_7: return "7";
+    case Key_8: return "8";
+    case Key_9: return "9";
+    case Key_Colon: return ":";
+    case Key_Semicolon: return ";";
+    case Key_LessThan: return "<";
+    case Key_Equal: return "=";
+    case Key_GreaterThan: return ">";
+    case Key_QuestionMark: return "?";
+    case Key_AtSign: return "@";
+    case Key_A: return "A";
+    case Key_B: return "B";
+    case Key_C: return "C";
+    case Key_D: return "D";
+    case Key_E: return "E";
+    case Key_F: return "F";
+    case Key_G: return "G";
+    case Key_H: return "H";
+    case Key_I: return "I";
+    case Key_J: return "J";
+    case Key_K: return "K";
+    case Key_L: return "L";
+    case Key_M: return "M";
+    case Key_N: return "N";
+    case Key_O: return "O";
+    case Key_P: return "P";
+    case Key_Q: return "Q";
+    case Key_R: return "R";
+    case Key_S: return "S";
+    case Key_T: return "T";
+    case Key_U: return "U";
+    case Key_V: return "V";
+    case Key_W: return "W";
+    case Key_X: return "X";
+    case Key_Y: return "Y";
+    case Key_Z: return "Z";
+    case Key_LeftBracket: return "[";
+    case Key_RightBracket: return "]";
+    case Key_Backslash: return "\\";
+    case Key_Circumflex: return "^";
+    case Key_Underscore: return "_";
+    case Key_LeftBrace: return "{";
+    case Key_RightBrace: return "}";
+    case Key_Pipe: return "|";
+    case Key_Tilde: return "~";
+    case Key_Backtick: return "`";
+
+    case Key_Invalid: return "Invalid";
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+String GShortcut::to_string() const
+{
+    Vector<String> parts;
+
+    if (m_modifiers & Mod_Ctrl)
+        parts.append("Ctrl");
+    if (m_modifiers & Mod_Shift)
+        parts.append("Shift");
+    if (m_modifiers & Mod_Alt)
+        parts.append("Alt");
+
+    parts.append(::to_string(m_key));
+
+    StringBuilder builder;
+    for (int i = 0; i < parts.size(); ++i) {
+        builder.append(parts[i]);
+        if (i != parts.size() - 1)
+            builder.append('+');
+    }
+    return builder.to_string();
+}
diff --git a/LibGUI/GShortcut.h b/LibGUI/GShortcut.h
new file mode 100644
index 0000000000..7675a6ef30
--- /dev/null
+++ b/LibGUI/GShortcut.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <Kernel/KeyCode.h>
+#include <AK/AKString.h>
+#include <AK/Traits.h>
+
+class GShortcut {
+public:
+    GShortcut() { }
+    GShortcut(unsigned modifiers, KeyCode key)
+        : m_modifiers(modifiers)
+        , m_key(key)
+    {
+    }
+
+    bool is_valid() const { return m_key != KeyCode::Key_Invalid; }
+    unsigned modifiers() const { return m_modifiers; }
+    KeyCode key() const { return m_key; }
+    String to_string() const;
+
+    bool operator==(const GShortcut& other) const
+    {
+        return m_modifiers == other.m_modifiers
+            && m_key == other.m_key;
+    }
+
+private:
+    unsigned m_modifiers { 0 };
+    KeyCode m_key { KeyCode::Key_Invalid };
+};
+
+namespace AK {
+
+template<>
+struct Traits<GShortcut> {
+    static unsigned hash(const GShortcut& shortcut)
+    {
+        return pair_int_hash(shortcut.modifiers(), shortcut.key());
+    }
+};
+
+}
diff --git a/LibGUI/Makefile b/LibGUI/Makefile
index 11a0bd563e..29e8b33006 100644
--- a/LibGUI/Makefile
+++ b/LibGUI/Makefile
@@ -31,6 +31,7 @@ LIBGUI_OBJS = \
     GTableView.o \
     GTableModel.o \
     GVariant.o \
+    GShortcut.o \
     GWindow.o
 
 OBJS = $(SHAREDGRAPHICS_OBJS) $(LIBGUI_OBJS)