magnifier.c

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/*
 * PROJECT:     ReactOS Magnify
 * LICENSE:     GPL - See COPYING in the top level directory
 * FILE:        base/applications/magnify/magnifier.c
 * PURPOSE:     Magnification of parts of the screen.
 * COPYRIGHT:   Copyright 2007 Marc Piulachs <marc.piulachs@codexchange.net>
 *
 */

#include "magnifier.h"

const TCHAR szWindowClass[] = TEXT("MAGNIFIER");

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;                                // current instance
HWND hMainWnd;

TCHAR szTitle[MAX_LOADSTRING];                  // The title bar text

#define REPAINT_SPEED   100

HWND hDesktopWindow = NULL;

//Current magnified area
POINT cp;

//Last positions
POINT pMouse;
POINT pCaret;
POINT pFocus;

// Forward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    AboutProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    OptionsProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    WarningProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // TODO: Place code here.
    MSG msg;
    HACCEL hAccelTable;

    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // Initialize global strings
    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_MAGNIFIER));

    // Main message loop:
    while (GetMessage(&msg, NULL, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



/*
 *  FUNCTION: MyRegisterClass()
 *
 *  PURPOSE: Registers the window class.
 *
 *  COMMENTS:
 *
 *    This function and its usage are only necessary if you want this code
 *    to be compatible with Win32 systems prior to the 'RegisterClassEx'
 *    function that was added to Windows 95. It is important to call this function
 *    so that the application will get 'well formed' small icons associated
 *    with it.
 */
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASS wc;

    wc.style            = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc      = WndProc;
    wc.cbClsExtra       = 0;
    wc.cbWndExtra       = 0;
    wc.hInstance        = hInstance;
    wc.hIcon            = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ICON));
    wc.hCursor          = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground    = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName     = MAKEINTRESOURCE(IDC_MAGNIFIER);
    wc.lpszClassName    = szWindowClass;

    return RegisterClass(&wc);
}

/*
 *  FUNCTION: InitInstance(HINSTANCE, int)
 *
 *  PURPOSE: Saves instance handle and creates main window
 *
 *   COMMENTS:
 *
 *        In this function, we save the instance handle in a global variable and
 *        create and display the main program window.
 */
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // Store instance handle in our global variable

    // Create the Window
   hMainWnd = CreateWindowEx(
        WS_EX_TOPMOST,
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL);

   if (!hMainWnd)
   {
      return FALSE;
   }

   ShowWindow(hMainWnd, (bStartMinimized) ? SW_MINIMIZE : nCmdShow);
   UpdateWindow(hMainWnd);

   if (bShowWarning)
   {
      DialogBox (hInstance, MAKEINTRESOURCE(IDD_WARNINGDIALOG), hMainWnd, (DLGPROC)WarningProc);
   }

   return TRUE;
}

void Refresh ()
{
    if (!IsIconic(hMainWnd))
    {
        // Invalidate the client area forcing a WM_PAINT message
        InvalidateRgn(hMainWnd, NULL, TRUE);
    }
}

void Draw(HDC aDc)
{
    HDC desktopHdc = NULL;
    HDC HdcStrech;
    HANDLE hOld;
    HBITMAP HbmpStrech;

    RECT R;
    RECT appRect;
    DWORD rop = SRCCOPY;
    CURSORINFO cinfo;
    ICONINFO iinfo;

    int Width, Height, AppWidth, AppHeight;
    LONG blitAreaWidth, blitAreaHeight, blitAreaX, blitAreaY;

    desktopHdc = GetWindowDC (hDesktopWindow);

    GetClientRect(hMainWnd, &appRect);
    GetWindowRect(hDesktopWindow, &R);

    ZeroMemory(&cinfo, sizeof(CURSORINFO));
    ZeroMemory(&iinfo, sizeof(ICONINFO));
    cinfo.cbSize = sizeof(cinfo);
    GetCursorInfo(&cinfo);
    GetIconInfo(cinfo.hCursor, &iinfo);

     /* Create a memory DC compatible with client area DC.*/
    HdcStrech = CreateCompatibleDC(desktopHdc);

    /* Create a bitmap compatible with the client area DC.*/
    HbmpStrech = CreateCompatibleBitmap(
        desktopHdc,
        R.right,
        R.bottom);

    /* Select our bitmap in memory DC and save the old one.*/
    hOld = SelectObject (HdcStrech , HbmpStrech);

    /* Paint the screen bitmap to our in memory DC */
    BitBlt(
        HdcStrech,
        0,
        0,
        R.right,
        R.bottom,
        desktopHdc,
        0,
        0,
        SRCCOPY);

    /* Draw the mouse pointer in the right position */
    DrawIcon(
        HdcStrech ,
        pMouse.x - iinfo.xHotspot, // - 10,
        pMouse.y - iinfo.yHotspot, // - 10,
        cinfo.hCursor);

    Width = (R.right - R.left);
    Height = (R.bottom - R.top);

    AppWidth = (appRect.right - appRect.left);
    AppHeight = (appRect.bottom - appRect.top);

    blitAreaWidth = AppWidth / iZoom;
    blitAreaHeight = AppHeight / iZoom;

    blitAreaX = (cp.x) - (blitAreaWidth /2);
    blitAreaY = (cp.y) - (blitAreaHeight /2);

    if (blitAreaX < 0)
    {
       blitAreaX = 0;
    }

    if (blitAreaY < 0)
    {
       blitAreaY = 0;
    }

    if (blitAreaX > (Width - blitAreaWidth))
    {
        blitAreaX = (Width - blitAreaWidth);
    }

    if (blitAreaY > (Height - blitAreaHeight))
    {
        blitAreaY = (Height - blitAreaHeight);
    }

    if (bInvertColors)
    {
        rop = NOTSRCCOPY;
    }

    /* Blast the stretched image from memory DC to window DC.*/
    StretchBlt(
        aDc,
        0,
        0,
        AppWidth,
        AppHeight,
        HdcStrech,
        blitAreaX,
        blitAreaY,
        blitAreaWidth,
        blitAreaHeight,
        rop);

    /* Cleanup.*/
    if (iinfo.hbmMask)
        DeleteObject(iinfo.hbmMask);
    if (iinfo.hbmColor)
        DeleteObject(iinfo.hbmColor);
    SelectObject (HdcStrech, hOld);
    DeleteObject (HbmpStrech);
    DeleteDC (HdcStrech);
    ReleaseDC(hDesktopWindow, desktopHdc);
}

/*
 *  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
 *
 *  PURPOSE:  Processes messages for the main window.
 *
 *  WM_COMMAND  - process the application menu
 *  WM_PAINT    - Paint the main window
 *  WM_DESTROY  - post a quit message and return
 *
 */
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId;

    switch (message)
    {
        case WM_TIMER:
        {
            POINT pNewMouse;
            POINT pNewCaret;
            POINT pNewFocus;
            HWND hwnd1, hwnd2, hwnd3;
            DWORD a, b;
            RECT controlRect;

            //Get current mouse position
            GetCursorPos (&pNewMouse);

            //Get caret position
            hwnd1 = GetForegroundWindow ();
            a = GetWindowThreadProcessId(hwnd1, NULL);
            b = GetCurrentThreadId();
            AttachThreadInput (a, b, TRUE);
            hwnd2 = GetFocus();

            GetCaretPos( &pNewCaret);
            ClientToScreen (hwnd2, (LPPOINT) &pNewCaret);
            AttachThreadInput (a, b, FALSE);

            //Get current control focus
            hwnd3 = GetFocus ();
            GetWindowRect (hwnd3 , &controlRect);
            pNewFocus.x = controlRect.left;
            pNewFocus.y = controlRect.top;

            //If mouse has moved ....
            if (((pMouse.x != pNewMouse.x) || (pMouse.y != pNewMouse.y)) && bFollowMouse)
            {
                //Update to new position
                pMouse = pNewMouse;
                cp = pNewMouse;
                Refresh();
            }
            else if (((pCaret.x != pNewCaret.x) || (pCaret.y != pNewCaret.y)) && bFollowCaret)
            {
                //Update to new position
                pCaret = pNewCaret;
                cp = pNewCaret;
                Refresh();
            }
            else if (((pFocus.x != pNewFocus.x) || (pFocus.y != pNewFocus.y)) && bFollowFocus)
            {
                //Update to new position
                pFocus = pNewFocus;
                cp = pNewFocus;
                Refresh();
            }
        }
        break;
    case WM_COMMAND:
        wmId    = LOWORD(wParam);
        // Parse the menu selections:
        switch (wmId)
        {
            case IDM_OPTIONS:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_DIALOGOPTIONS), hWnd, (DLGPROC)OptionsProc);
                break;
            case IDM_ABOUT:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, (DLGPROC)AboutProc);
                break;
            case IDM_EXIT:
                DestroyWindow(hWnd);
                break;
            default:
                return DefWindowProc(hWnd, message, wParam, lParam);
        }
        break;
   case WM_PAINT:
        {
            PAINTSTRUCT PaintStruct;
            HDC dc;
            dc = BeginPaint(hWnd, &PaintStruct);
            Draw(dc);
            EndPaint(hWnd, &PaintStruct);
        }
      break;
   case WM_ERASEBKGND:
        //handle WM_ERASEBKGND by simply returning non-zero because we did all the drawing in WM_PAINT.
       break;
    case WM_DESTROY:
        //Save settings to registry
        SaveSettings ();
        KillTimer (hWnd , 1);
        PostQuitMessage(0);
        break;
    case WM_CREATE:
            //Load settings from registry
            LoadSettings ();

            //Get the desktop window
            hDesktopWindow = GetDesktopWindow();

            //Set the timer
            SetTimer (hWnd , 1, REPAINT_SPEED , NULL);
            break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// Message handler for about box.
INT_PTR CALLBACK AboutProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
    case WM_INITDIALOG:
        return (INT_PTR)TRUE;

    case WM_COMMAND:
        if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
        {
            EndDialog(hDlg, LOWORD(wParam));
            return (INT_PTR)TRUE;
        }
        break;
    }
    return (INT_PTR)FALSE;
}

// Message handler for options box.
INT_PTR CALLBACK OptionsProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
        case WM_INITDIALOG:
        {
            //Add the zoom items....
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("1"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("2"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("3"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("4"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("5"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("6"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("7"));
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_ADDSTRING, 0, (LPARAM)("8"));

            //
            SendDlgItemMessage(hDlg, IDC_ZOOM, CB_SETCURSEL, iZoom - 1, 0);

            if (bFollowMouse)
                SendDlgItemMessage(hDlg,IDC_FOLLOWMOUSECHECK,BM_SETCHECK , wParam ,0);

            if (bFollowFocus)
                SendDlgItemMessage(hDlg,IDC_FOLLOWKEYBOARDCHECK,BM_SETCHECK , wParam ,0);

            if (bFollowCaret)
                SendDlgItemMessage(hDlg,IDC_FOLLOWTEXTEDITINGCHECK,BM_SETCHECK , wParam ,0);

            if (bInvertColors)
                SendDlgItemMessage(hDlg,IDC_INVERTCOLORSCHECK,BM_SETCHECK , wParam ,0);

            if (bStartMinimized)
                SendDlgItemMessage(hDlg,IDC_STARTMINIMIZEDCHECK,BM_SETCHECK , wParam ,0);

            if (bShowMagnifier)
                SendDlgItemMessage(hDlg,IDC_SHOWMAGNIFIERCHECK,BM_SETCHECK , wParam ,0);

            return (INT_PTR)TRUE;
        }
    case WM_COMMAND:
        switch(LOWORD(wParam))
        {
            case IDOK:
            case IDCANCEL:
                EndDialog(hDlg, LOWORD(wParam));
                return (INT_PTR)TRUE;

            case IDC_BUTTON_HELP:
                /* unimplemented */
                MessageBox(hDlg , TEXT("Magnifier help not available yet!") , TEXT("Help") , MB_OK);
                break;
            case IDC_ZOOM:
                if(HIWORD(wParam) == CBN_SELCHANGE)
                {
                    HWND hCombo = GetDlgItem(hDlg,IDC_ZOOM);

                    /* Get index of current selection and the text of that selection. */
                    iZoom = SendMessage( hCombo, CB_GETCURSEL, (WPARAM) wParam, (LPARAM) lParam ) + 1;

                    //Update the magnigier UI
                    Refresh ();
                }
                break;
            case IDC_INVERTCOLORSCHECK:
                bInvertColors = IsDlgButtonChecked (hDlg, IDC_INVERTCOLORSCHECK);
                Refresh ();
                break;
            case IDC_FOLLOWMOUSECHECK:
                bFollowMouse = IsDlgButtonChecked (hDlg, IDC_FOLLOWMOUSECHECK);
                break;
            case IDC_FOLLOWKEYBOARDCHECK:
                bFollowFocus = IsDlgButtonChecked (hDlg, IDC_FOLLOWKEYBOARDCHECK);
                break;
            case IDC_FOLLOWTEXTEDITINGCHECK:
                bFollowCaret = IsDlgButtonChecked (hDlg, IDC_FOLLOWTEXTEDITINGCHECK);
                break;
            case IDC_STARTMINIMIZEDCHECK:
                bStartMinimized = IsDlgButtonChecked (hDlg, IDC_STARTMINIMIZEDCHECK);
                break;
            case IDC_SHOWMAGNIFIER:
                bShowMagnifier = IsDlgButtonChecked (hDlg, IDC_SHOWMAGNIFIERCHECK);
                if (bShowMagnifier){
                    ShowWindow (hMainWnd , SW_SHOW);
                }else{
                    ShowWindow (hMainWnd , SW_HIDE);
                }
                break;
        }
    }
    return (INT_PTR)FALSE;
}

// Message handler for warning box.
INT_PTR CALLBACK WarningProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);

    switch (message)
    {
        case WM_INITDIALOG:
            return (INT_PTR)TRUE;
        case WM_COMMAND:
            switch(LOWORD(wParam))
            {
                case IDC_SHOWWARNINGCHECK:
                    bShowWarning = !IsDlgButtonChecked (hDlg, IDC_SHOWWARNINGCHECK);
                    break;
            }
            if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
            {
                EndDialog(hDlg, LOWORD(wParam));
                return (INT_PTR)TRUE;
            }
            break;
    }
    return (INT_PTR)FALSE;
}