Start working on a GUI kernel API.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/8f8c8d1ca34

Kernel/GUITypes.h

@@ -0,0 +1,23 @@
+#pragma once
+
+// GUI system call API types.
+
+struct GUI_Rect {
+    int x;
+    int y;
+    int width;
+    int height;
+};
+
+struct GUI_WindowFlags { enum {
+    Visible = 1 << 0,
+}; };
+
+typedef unsigned GUI_Color;
+
+struct GUI_CreateWindowParameters {
+    GUI_Rect rect;
+    GUI_Color background_color;
+    unsigned flags;
+    char title[128];
+};

Kernel/Makefile

@@ -5,6 +5,7 @@ KERNEL_OBJS = \
        StdLib.o \
        i386.o \
        Process.o \
+       ProcessGUI.o \
        i8253.o \
        Keyboard.o \
        CMOS.o \

Kernel/Process.cpp

@@ -54,6 +54,7 @@ void Process::initialize()
     g_processes = new InlineLinkedList<Process>;
     s_hostname = new String("courage");
     Scheduler::initialize();
+    initialize_gui_statics();
 }
 
 Vector<Process*> Process::allProcesses()

Kernel/Process.h

@@ -5,6 +5,7 @@
 #include "i386.h"
 #include "TTY.h"
 #include "Syscall.h"
+#include "GUITypes.h"
 #include <VirtualFileSystem/VirtualFileSystem.h>
 #include <VirtualFileSystem/UnixTypes.h>
 #include <AK/InlineLinkedList.h>
@@ -16,6 +17,7 @@ class PageDirectory;
 class Region;
 class VMObject;
 class Zone;
+class Window;
 
 #define COOL_GLOBALS
 #ifdef COOL_GLOBALS
@@ -185,9 +187,13 @@ public:
     Unix::clock_t sys$times(Unix::tms*);
     int sys$utime(const char* pathname, const struct Unix::utimbuf*);
 
+    int gui$create_window(const GUI_CreateWindowParameters*);
+    int gui$destroy_window(int window_id);
+
     DisplayInfo get_display_info();
 
     static void initialize();
+    static void initialize_gui_statics();
 
     void crash() NORETURN;
     static int reap(Process&) WARN_UNUSED_RESULT;
@@ -331,6 +337,8 @@ private:
     Region* m_signal_stack_kernel_region { nullptr };
 
     RetainPtr<Region> m_display_framebuffer_region;
+
+    Vector<Window*> m_windows;
 };
 
 extern Process* current;

Kernel/ProcessGUI.cpp

@@ -0,0 +1,77 @@
+#include "Process.h"
+#include "MemoryManager.h"
+#include <LibC/errno_numbers.h>
+#include <Widgets/AbstractScreen.h>
+#include <Widgets/FrameBuffer.h>
+#include <Widgets/EventLoop.h>
+#include <Widgets/Font.h>
+#include <Widgets/Widget.h>
+#include <Widgets/Window.h>
+#include <Widgets/WindowManager.h>
+
+void Process::initialize_gui_statics()
+{
+    Font::initialize();
+    FrameBuffer::initialize();
+    EventLoop::initialize();
+    WindowManager::initialize();
+    AbstractScreen::initialize();
+
+    new EventLoop;
+}
+
+static void wait_for_gui_server()
+{
+    // FIXME: Time out after a while and return an error.
+    while (!EventLoop::main().running())
+        sleep(10);
+}
+
+int Process::gui$create_window(const GUI_CreateWindowParameters* user_params)
+{
+    wait_for_gui_server();
+
+    if (!validate_read_typed(user_params))
+        return -EFAULT;
+
+    GUI_CreateWindowParameters params = *user_params;
+    Rect rect { params.rect.x, params.rect.y, params.rect.width, params.rect.height };
+
+    if (rect.is_empty())
+        return -EINVAL;
+
+    ProcessPagingScope scope(EventLoop::main().server_process());
+
+    auto* window = new Window;
+    if (!window)
+        return -ENOMEM;
+
+    int window_id = m_windows.size();
+    m_windows.append(window);
+
+    window->setTitle(params.title);
+    window->setRect(rect);
+
+    auto* main_widget = new Widget;
+    window->setMainWidget(main_widget);
+    main_widget->setWindowRelativeRect({ 0, 0, rect.width(), rect.height() });
+    main_widget->setBackgroundColor(params.background_color);
+    main_widget->setFillWithBackgroundColor(true);
+    dbgprintf("%s<%u> gui$create_window: %d with rect {%d,%d %dx%d}\n", name().characters(), pid(), window_id, rect.x(), rect.y(), rect.width(), rect.height());
+
+    return window_id;
+}
+
+int Process::gui$destroy_window(int window_id)
+{
+    wait_for_gui_server();
+    dbgprintf("%s<%u> gui$destroy_window (window_id=%d)\n", name().characters(), pid(), window_id);
+    if (window_id < 0)
+        return -EINVAL;
+    if (window_id >= static_cast<int>(m_windows.size()))
+        return -EBADWIN;
+    auto* window = m_windows[window_id];
+    m_windows.remove(window_id);
+    window->deleteLater();
+    return 0;
+}

Kernel/Syscall.cpp

@@ -187,6 +187,10 @@ static dword handle(RegisterDump& regs, dword function, dword arg1, dword arg2,
         return current->sys$utime((const char*)arg1, (const Unix::utimbuf*)arg2);
     case Syscall::SC_sync:
         return sync();
+    case Syscall::SC_gui_create_window:
+        return current->gui$create_window((const GUI_CreateWindowParameters*)arg1);
+    case Syscall::SC_gui_destroy_window:
+        return current->gui$destroy_window((int)arg1);
     default:
         kprintf("<%u> int0x80: Unknown function %u requested {%x, %x, %x}\n", current->pid(), function, arg1, arg2, arg3);
         break;

Kernel/Syscall.h

@@ -66,6 +66,8 @@
     __ENUMERATE_SYSCALL(times) \
     __ENUMERATE_SYSCALL(utime) \
     __ENUMERATE_SYSCALL(sync) \
+    __ENUMERATE_SYSCALL(gui_create_window) \
+    __ENUMERATE_SYSCALL(gui_destroy_window) \
 
 namespace Syscall {
 

Kernel/WindowComposer.cpp

@@ -14,18 +14,11 @@
 
 void WindowComposer_main()
 {
-    Font::initialize();
-    FrameBuffer::initialize();
-    EventLoop::initialize();
-    WindowManager::initialize();
-    AbstractScreen::initialize();
-
     auto info = current->get_display_info();
 
     dbgprintf("Screen is %ux%ux%ubpp\n", info.width, info.height, info.bpp);
 
     FrameBuffer framebuffer((dword*)info.framebuffer, info.width, info.height);
-    EventLoop loop;
 
     MsgBox(nullptr, "Serenity Operating System");
 
@@ -75,7 +68,7 @@ void WindowComposer_main()
     }
 
     dbgprintf("Entering WindowComposer main loop.\n");
-    loop.exec();
+    EventLoop::main().exec();
 
     ASSERT_NOT_REACHED();
 }

Kernel/init.cpp

@@ -22,6 +22,7 @@
 #include "Scheduler.h"
 #include "PS2MouseDevice.h"
 
+#define SPAWN_GUI_TEST_APP
 //#define SPAWN_MULTIPLE_SHELLS
 //#define STRESS_TEST_SPAWNING
 
@@ -94,6 +95,9 @@ static void init_stage2()
 
     int error;
     Process::create_user_process("/bin/sh", (uid_t)100, (gid_t)100, (pid_t)0, error, { }, move(environment), tty0);
+#ifdef SPAWN_GUI_TEST_APP
+    Process::create_user_process("/bin/guitest", (uid_t)100, (gid_t)100, (pid_t)0, error, { }, move(environment), tty0);
+#endif
 #ifdef SPAWN_MULTIPLE_SHELLS
     Process::create_user_process("/bin/sh", (uid_t)100, (gid_t)100, (pid_t)0, error, { }, { }, tty1);
     Process::create_user_process("/bin/sh", (uid_t)100, (gid_t)100, (pid_t)0, error, { }, { }, tty2);

Kernel/sync.sh

@@ -30,6 +30,7 @@ cp -v ../Userland/mkdir mnt/bin/mkdir
 cp -v ../Userland/touch mnt/bin/touch
 cp -v ../Userland/sync mnt/bin/sync
 cp -v ../Userland/more mnt/bin/more
+cp -v ../Userland/guitest mnt/bin/guitest
 sh sync-local.sh
 cp -v kernel.map mnt/
 ln -s dir_a mnt/dir_cur

LibC/errno_numbers.h

@@ -42,6 +42,7 @@
     __ERROR(ENOTIMPL,       "Not implemented") \
     __ERROR(EAFNOSUPPORT,   "Address family not supported") \
     __ERROR(EWHYTHO,        "Failed without setting an error code (Bug!)") \
+    __ERROR(EBADWIN,        "Bad WindowID") \
 
 enum __errno_values {
 #undef __ERROR

Userland/Makefile

@@ -18,7 +18,8 @@ OBJS = \
        tty.o \
        mkdir.o \
        touch.o \
-       more.o
+       more.o \
+       guitest.o
 
 APPS = \
        id \
@@ -41,7 +42,8 @@ APPS = \
        mkdir \
        touch \
        sync \
-       more
+       more \
+       guitest
 
 ARCH_FLAGS =
 STANDARD_FLAGS = -std=c++17 -nostdinc++ -nostdlib -nostdinc
@@ -124,6 +126,9 @@ sync: sync.o
 more: more.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 
+guitest: guitest.o
+	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
+
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 

Widgets/Color.h

@@ -22,6 +22,7 @@ public:
     Color() { }
     Color(NamedColor);
     Color(byte r, byte g, byte b);
+    Color(RGBA32 rgba) : m_value(rgba) { }
 
     RGBA32 value() const { return m_value; }
 

Widgets/EventLoop.cpp

@@ -6,6 +6,7 @@
 
 #ifdef SERENITY
 #include "PS2MouseDevice.h"
+#include "Scheduler.h"
 #endif
 
 static EventLoop* s_mainEventLoop;
@@ -33,6 +34,10 @@ EventLoop& EventLoop::main()
 
 int EventLoop::exec()
 {
+#ifdef SERENITY
+    m_server_process = current;
+#endif
+    m_running = true;
     for (;;) {
         if (m_queuedEvents.is_empty())
             waitForEvent();
@@ -48,9 +53,11 @@ int EventLoop::exec()
             if (!receiver) {
                 switch (event.type()) {
                 case Event::Quit:
+                    ASSERT_NOT_REACHED();
                     return 0;
                 default:
                     printf("event type %u with no receiver :(\n", event.type());
+                    ASSERT_NOT_REACHED();
                     return 1;
                 }
             } else {

Widgets/EventLoop.h

@@ -9,6 +9,7 @@
 #endif
 
 class Object;
+class Process;
 
 class EventLoop {
 public:
@@ -23,6 +24,9 @@ public:
 
     static void initialize();
 
+    bool running() const { return m_running; }
+    Process& server_process() { return *m_server_process; }
+
 private:
     void waitForEvent();
 
@@ -35,4 +39,7 @@ private:
         OwnPtr<Event> event;
     };
     Vector<QueuedEvent> m_queuedEvents;
+
+    Process* m_server_process { nullptr };
+    bool m_running { false };
 };

Widgets/GraphicsBitmap.cpp

@@ -1,4 +1,5 @@
 #include "GraphicsBitmap.h"
+#include "EventLoop.h"
 #include <AK/kmalloc.h>
 
 #ifdef SERENITY
@@ -21,7 +22,9 @@ GraphicsBitmap::GraphicsBitmap(const Size& size)
     , m_pitch(size.width() * sizeof(RGBA32))
 {
 #ifdef SERENITY
-    m_region = current->allocate_region(LinearAddress(), size.width() * size.height() * sizeof(RGBA32), "GraphicsBitmap", true, true, true);
+    // FIXME: Oh god this is so horrible.
+    Process* server_process = EventLoop::main().running() ? &EventLoop::main().server_process() : current;
+    m_region = server_process->allocate_region(LinearAddress(), size.width() * size.height() * sizeof(RGBA32), "GraphicsBitmap", true, true, true);
     m_data = (RGBA32*)m_region->linearAddress.asPtr();
     m_owned = false;
 #else

Widgets/Window.cpp

@@ -43,6 +43,7 @@ void Window::setRect(const Rect& rect)
         return;
     auto oldRect = m_rect;
     m_rect = rect;
+    dbgprintf("Window::setRect %d,%d %dx%d\n", m_rect.x(), m_rect.y(), m_rect.width(), m_rect.height());
     m_backing = GraphicsBitmap::create(m_rect.size());
     WindowManager::the().notifyRectChanged(*this, oldRect, m_rect);
 }