import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Create new implementation instance for the given GameCanvas
 * @param c GameCanvas instance to create the implementation for
 */ 
public GameCanvasLFImpl(GameCanvas c) {
    owner = c;
    graphicsAccess = GameMap.getGraphicsAccess();


    /* IMPL_NOTE: The initial off-screen buffer has the same width
     *   and height as the entire screen. Further resizing will not
     *   cause memory reallocation until new geometry is bigger than
     *   the current one. Screen rotation is one of the cases the
     *   reallocation is needed.
     *
     *   User can override the methods getWidth() and getHeight() of
     *   GameCanvas, so they should not be used for off-screen buffer
     *   initial allocation.
     */
    offscreenBuffer = Image.createImage(
        graphicsAccess.getScreenWidth(),
        graphicsAccess.getScreenHeight());
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
public void flushGraphics(GameCanvas gameCanvas, int x, int y, int width, int height) {
    AndroidCanvasUI ui = ((AndroidCanvasUI) DisplayUtils.getDisplayableUI(gameCanvas));
    CanvasView canvasView = (CanvasView) ui.getView();
    if (canvasView != null) {
        canvasView.flushGraphics(x, y, width, height);
    }
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Gets the GameCanvasLFImpl object for this GameCanvas.
 * @param c The GameCanvas to get the GameCanvasLFImpl for
 * @return GameCanvasLFImpl, or null if there is no accessor to game package
 */
public static GameCanvasLFImpl getGameCanvasImpl(GameCanvas c) {
    if (gameAccess != null) {
        return gameAccess.getGameCanvasLFImpl(c);
    }
    return null;
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Prepare to show this LF on physical screen. This is the
 * internal version of showNotify() function as defined in MIDP spec.
 * It is called immediately prior to this LF being made visible
 * on the display. The LF should load any resource that is
 * needed, layout. App's paint() should NOT be called in this function.
 * Instead, it should be in the uCallPaint() that will be called on this
 * LF shortly after.
 *
 * This function sets this DisplayableLF to SHOWN state.
 */
void lCallShow() {

    // This will suppress drags, repeats and ups until a
    // corresponding down is seen.
    sawPointerPress = sawKeyPress = false;
    
    if (state != SHOWN) {
        // Create native resource first
        // since the title and ticker may depend on it
        createNativeResource();
    }

    // Start to paint the ticker
    updateNativeTicker(null, owner.ticker);

    // set mapping between GameCanvas and DisplayAccess
    // set Game key event flag based on value passed in
    // GameCanvas constructor.
    if (owner instanceof GameCanvas) {
        GameMap.registerDisplayAccess(owner, currentDisplay.accessor);
        stickyKeyMask = currentKeyMask = 0;
    } else {
        // set the keymask to -1 when
        // the displayable is not a GameCanvas.
        stickyKeyMask = currentKeyMask = -1;
    }

    state = SHOWN;
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Called to release key mask of all the keys that were release.
 *
 * @param keyCode The key code to release the key mask.
 */
private void releaseKeyMask(int keyCode) {
    /*
    // Leave this case to dsHide and dsFreeze()
    if (paintSuspended || !hasForeground) {
        currentKeyMask = 0;
        return;
    }
    */

    // set the mask of keys pressed 
    switch (KeyConverter.getGameAction(keyCode)) {
    case Canvas.UP:
        currentKeyMask = currentKeyMask & ~ GameCanvas.UP_PRESSED;
        break;
    case Canvas.DOWN:
        currentKeyMask = currentKeyMask & ~ GameCanvas.DOWN_PRESSED;
        break;
    case Canvas.LEFT:
        currentKeyMask = currentKeyMask & ~ GameCanvas.LEFT_PRESSED;
        break;
    case Canvas.RIGHT:
        currentKeyMask = currentKeyMask & ~ GameCanvas.RIGHT_PRESSED;
        break;
    case Canvas.FIRE:
        currentKeyMask = currentKeyMask & ~ GameCanvas.FIRE_PRESSED;
        break;
    case Canvas.GAME_A:
        currentKeyMask = currentKeyMask & ~ GameCanvas.GAME_A_PRESSED;
        break;
    case Canvas.GAME_B:
        currentKeyMask = currentKeyMask & ~ GameCanvas.GAME_B_PRESSED;
        break;
    case Canvas.GAME_C:
        currentKeyMask = currentKeyMask & ~ GameCanvas.GAME_C_PRESSED;
        break;
    case Canvas.GAME_D:
        currentKeyMask = currentKeyMask & ~ GameCanvas.GAME_D_PRESSED;
    }
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
public Graphics getGraphics(GameCanvas gameCanvas)
{
    return ((AndroidCanvasUI) DisplayUtils.getDisplayableUI(gameCanvas)).getGraphics();
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Package private equivalent of sizeChanged().
 *
 * @param w the new width
 * @param h the new height
 *
 */
public void uCallSizeChanged(int w, int h) {

    boolean copyDefferedSizeChange;

    synchronized (Display.LCDUILock) {
        if (owner instanceof GameCanvas) {
            GameCanvasLFImpl gameCanvasLF =
                GameMap.getGameCanvasImpl((GameCanvas)owner);
            if (gameCanvasLF != null) {
                gameCanvasLF.lCallSizeChanged(w, h);
            }
        }

        // If there is no Display, or if this Displayable is not
        // currently visible, we simply record the fact that the
        // size has changed
        defferedSizeChange = (state != SHOWN);
        copyDefferedSizeChange = defferedSizeChange;
        /*
         * sizeChangeOccurred is a boolean which (when true) indicates
         * that sizeChanged() will be called at a later time. So, if it
         * is false after calling super(), we go ahead and notify the
         * Canvas now, rather than later
         */

        width = w;
        height = h;
        if (!defferedSizeChange) {
            lRequestInvalidate();
        }

    }
    if (!copyDefferedSizeChange) {
        synchronized (Display.calloutLock) {
            try {
                owner.sizeChanged(w, h);
            } catch (Throwable t) {
                Display.handleThrowable(t);
            }
        }
    }
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Called to set key mask of all the keys that were pressed.
 *
 * @param keyCode The key code to set the key mask.
 */
private void setKeyMask(int keyCode) {
    /*
    // Shouldn't run into this case.
    if (paintSuspended || !hasForeground) {
        return;
    }
    */

    // set the mask of keys pressed 
    switch (KeyConverter.getGameAction(keyCode)) {
    case Canvas.UP:
        stickyKeyMask = stickyKeyMask | GameCanvas.UP_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.UP_PRESSED;
        break;
    case Canvas.DOWN:
        stickyKeyMask = stickyKeyMask | GameCanvas.DOWN_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.DOWN_PRESSED;
        break;
    case Canvas.LEFT:
        stickyKeyMask = stickyKeyMask | GameCanvas.LEFT_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.LEFT_PRESSED;
        break;
    case Canvas.RIGHT:
        stickyKeyMask = stickyKeyMask | GameCanvas.RIGHT_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.RIGHT_PRESSED;
        break;
    case Canvas.FIRE:
        stickyKeyMask = stickyKeyMask | GameCanvas.FIRE_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.FIRE_PRESSED;
        break;
    case Canvas.GAME_A:
        stickyKeyMask = stickyKeyMask | GameCanvas.GAME_A_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.GAME_A_PRESSED;
        break;
    case Canvas.GAME_B:
        stickyKeyMask = stickyKeyMask | GameCanvas.GAME_B_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.GAME_B_PRESSED;
        break;
    case Canvas.GAME_C:
        stickyKeyMask = stickyKeyMask | GameCanvas.GAME_C_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.GAME_C_PRESSED;
        break;
    case Canvas.GAME_D:
        stickyKeyMask = stickyKeyMask | GameCanvas.GAME_D_PRESSED;
        currentKeyMask = currentKeyMask | GameCanvas.GAME_D_PRESSED;
    }
}
 

import javax.microedition.lcdui.game.GameCanvas; //导入依赖的package包/类
/**
 * Get implementation of the given GameCanvas
 *
 * @param gameCanvas GameCanvas to get the internal implementation
 * @return GameCanvasLFImpl instance of the given GameCanvas
 */
public GameCanvasLFImpl getGameCanvasLFImpl(GameCanvas gameCanvas);