minigui/mgncs:双缓冲区实现窗口推拉特效

#include <unistd.h>
#include <minigui/common.h>
#include <minigui/minigui.h>
#include <minigui/gdi.h>
#include <minigui/window.h>
#include <mgncs/mgncs.h>
#include "resource.h"
#include "ncs-windows.h"
// 获取窗口hWnd矩形坐标并转为基于屏幕的坐标
static PRECT fl_get_screen_rect(HWND hWnd, PRECT prect)
{
    GetWindowRect(hWnd,prect);
    HWND parent = GetParent(hWnd);
    WindowToScreen(parent,&prect->left,&prect->top);
    WindowToScreen(parent,&prect->right,&prect->bottom);
	return prect;
}
/**
 * 窗口水平向左推入,hwnd需要WS_EX_AUTOSECONDARYDC窗口风格
 */
static void screen_pull (HWND hwnd)
{
	// 只对双缓冲区窗口有效
	if(!(GetWindowExStyle(hwnd) & WS_EX_AUTOSECONDARYDC))
	    return;
    MSG msg;
    HDC sec_dc;

    /* 这里通过设置ON_UPDSECDC_DONOTHING，
     * 禁止ShowWindow函数将新窗口内容输出到屏幕，而只是画到SecondaryDC 
     * 再在后面的循环中将SecondaryDC中的内容一步一步画到屏幕DC.
     */
    sec_dc = GetSecondaryDC (hwnd);
    SetSecondaryDC (hwnd, sec_dc, ON_UPDSECDC_DONOTHING);

    /* get the content of the active main window */
    ShowWindow (hwnd, SW_SHOWNORMAL);
    /* wait for MSG_IDLE */
    while (GetMessage (&msg, hwnd)) {
        if (msg.message == MSG_IDLE)
            break;
        DispatchMessage (&msg);
    }
    RECT scr_rect;
    fl_get_screen_rect(hwnd,&scr_rect);
    RECT win_rect;
    GetWindowRect(hwnd,&win_rect);
	int w = scr_rect.right -scr_rect.left;
	int h = scr_rect.bottom-scr_rect.top;
    /* 直接输出到屏幕DC,实现从从右向左推拉显示，间隔100毫秒 */
    for(int shift=0;shift <= w;shift+=20)
    {
        BitBlt (sec_dc, 0, 0, shift, h,
        		HDC_SCREEN, scr_rect.right - shift, 0, 0);
        usleep (100000);
    }
    /* 函数结束时要恢SecondaryDC的默认更新方式：ON_UPDSECDC_DEFAULT */
    SetSecondaryDC (hwnd, sec_dc, ON_UPDSECDC_DEFAULT);
}

int myCreateModalDialogFromID (HPACKAGE package, Uint32 dlgId,
                    HWND owner,
                    NCS_EVENT_HANDLER_INFO* handlers,
					DWORD user_data)
{
    int ret = 0;
    mDialogBox * dialog = SAFE_CAST(mDialogBox,
    		ncsCreateMainWindowIndirectFromID(package,dlgId,owner,(HICON)0,(HMENU)0,handlers,user_data));
    if (dialog) {
    	screen_pull(dialog->hwnd);
        ret = _c(dialog)->doModal(dialog, TRUE);
        if(IsMainWindow(dialog->hwnd)){
        	MainWindowThreadCleanup(dialog->hwnd);
        }
    }
    return ret;
}