tools/viewer/sk_app/unix/Window_unix.cpp

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/

//#include <tchar.h>

#include "SkUtils.h"
#include "Timer.h"
#include "../VulkanWindowContext.h"
#include "Window_unix.h"

extern "C" {
    #include "keysym2ucs.h"
}
#include <X11/Xutil.h>
#include <X11/XKBlib.h>

namespace sk_app {

SkTDynamicHash<Window_unix, XWindow> Window_unix::gWindowMap;

Window* Window::CreateNativeWindow(void* platformData) {
    Display* display = (Display*)platformData;

    Window_unix* window = new Window_unix();
    if (!window->init(display)) {
        delete window;
        return nullptr;
    }

    return window;
}

bool Window_unix::init(Display* display) {
    fDisplay = display;

    fWidth = 1280;
    fHeight = 960;
    fHWnd = XCreateSimpleWindow(display, DefaultRootWindow(display), 0, 0, fWidth, fHeight, 
                                0, BlackPixel(display, DefaultScreen(display)), 
                                BlackPixel(display, DefaultScreen(display)));

    if (!fHWnd) {
        return false;
    }

    // choose the events we care about
    XSelectInput(display, fHWnd, 
                 ExposureMask | StructureNotifyMask | KeyPressMask | KeyReleaseMask | 
                 PointerMotionMask | ButtonPressMask | ButtonReleaseMask);

    // set up to catch window delete message
    fWmDeleteMessage = XInternAtom(display, "WM_DELETE_WINDOW", False);
    XSetWMProtocols(display, fHWnd, &fWmDeleteMessage, 1);

    // add to hashtable of windows
    gWindowMap.add(this);

    // init event variables
    fPendingPaint = false;
    fPendingResize = false;

    return true;
}

static Window::Key get_key(KeySym keysym) {
    static const struct {
        KeySym      fXK;
        Window::Key fKey;
    } gPair[] = {
        { XK_BackSpace, Window::Key::kBack },
        { XK_Clear, Window::Key::kBack },
        { XK_Return, Window::Key::kOK },
        { XK_Up, Window::Key::kUp },
        { XK_Down, Window::Key::kDown },
        { XK_Left, Window::Key::kLeft },
        { XK_Right, Window::Key::kRight }
    };
    for (size_t i = 0; i < SK_ARRAY_COUNT(gPair); i++) {
        if (gPair[i].fXK == keysym) {
            return gPair[i].fKey;
        }
    }
    return Window::Key::kNONE;
}

static uint32_t get_modifiers(const XEvent& event) {
    static const struct {
        unsigned    fXMask;
        unsigned    fSkMask;
    } gModifiers[] = {
        { ShiftMask,   Window::kShift_ModifierKey },
        { ControlMask, Window::kControl_ModifierKey },
        { Mod1Mask,    Window::kOption_ModifierKey },
    };

    auto modifiers = 0;
    for (size_t i = 0; i < SK_ARRAY_COUNT(gModifiers); ++i) {
        if (event.xkey.state & gModifiers[i].fXMask) {
            modifiers |= gModifiers[i].fSkMask;
        }
    }
    return modifiers;
}

bool Window_unix::handleEvent(const XEvent& event) {
    switch (event.type) {
        case ClientMessage:
            if ((Atom)event.xclient.data.l[0] == fWmDeleteMessage &&
                gWindowMap.count() == 1) {
                return true;
            }
            break;

        case ButtonPress:
            if (event.xbutton.button == Button1) {
                this->onMouse(event.xbutton.x, event.xbutton.y,
                              Window::kDown_InputState, get_modifiers(event));
            }
            break;

        case ButtonRelease:
            if (event.xbutton.button == Button1) {
                this->onMouse(event.xbutton.x, event.xbutton.y,
                              Window::kUp_InputState, get_modifiers(event));
            }
            break;

        case MotionNotify:
            // only track if left button is down
            if (event.xmotion.state & Button1Mask) {
                this->onMouse(event.xmotion.x, event.xmotion.y, 
                              Window::kMove_InputState, get_modifiers(event));
            }
            break;

        case KeyPress: {
            int shiftLevel = (event.xkey.state & ShiftMask) ? 1 : 0;
            KeySym keysym = XkbKeycodeToKeysym(fDisplay, event.xkey.keycode,
                                               0, shiftLevel);
            if (keysym == XK_Escape) {
                return true;
            }
            Window::Key key = get_key(keysym);
            if (key != Window::Key::kNONE) {
                (void) this->onKey(key, Window::kDown_InputState, 
                                   get_modifiers(event));
            } else {
                long uni = keysym2ucs(keysym);
                if (uni != -1) {
                    (void) this->onChar((SkUnichar) uni, 
                                        get_modifiers(event));
                }
            }
        } break;

        case KeyRelease: {
            int shiftLevel = (event.xkey.state & ShiftMask) ? 1 : 0;
            KeySym keysym = XkbKeycodeToKeysym(fDisplay, event.xkey.keycode,
                                               0, shiftLevel);
            Window::Key key = get_key(keysym);
            (void) this->onKey(key, Window::kUp_InputState, 
                               get_modifiers(event));
        } break;
        

        default:
            // these events should be handled in the main event loop
            SkASSERT(event.type != Expose && event.type != ConfigureNotify);
            break;
    }

    return false;
}

void Window_unix::setTitle(const char* title) {
    XTextProperty textproperty;
    XStringListToTextProperty(const_cast<char**>(&title), 1, &textproperty);
    XSetWMName(fDisplay, fHWnd, &textproperty);    
}

void Window_unix::show() {
    XMapWindow(fDisplay, fHWnd);
}

bool Window_unix::attach(BackendType attachType, const DisplayParams& params) {
    ContextPlatformData_unix platformData;
    platformData.fDisplay = fDisplay;
    platformData.fHWnd = fHWnd;
    XWindowAttributes attribs;
    XGetWindowAttributes(fDisplay, fHWnd, &attribs);
    platformData.fVisualID = XVisualIDFromVisual(attribs.visual);
    switch (attachType) {
        case kVulkan_BackendType:
        default:
            fWindowContext = VulkanWindowContext::Create((void*)&platformData, params);
            break;
    }

    return (SkToBool(fWindowContext));
}

void Window_unix::onInval() {
    XEvent event;
    event.type = Expose;
    event.xexpose.send_event = True;
    event.xexpose.display = fDisplay;
    event.xexpose.window = fHWnd;
    event.xexpose.x = 0;
    event.xexpose.y = 0;
    event.xexpose.width = fWidth;
    event.xexpose.height = fHeight;
    event.xexpose.count = 0;
    
    XSendEvent(fDisplay, fHWnd, False, 0, &event);
}

}   // namespace sk_app