Mosaic: Creating the main frame
Now we will create the main frame of our program:
Add two prototypes after the includes:
WndProc PROTO STDCALL :DWORD, :DWORD, :DWORD, :DWORD
These prototypes will tell masm how many parameters these functions take (4 DWORD's in this case)
Add these to the .data and .data? sections of your program:
AppName db "Mosaic",0
ClassName db "Mosaic32",0
.data?
hInstance dd ?
AppName and ClassName are strings used for the main window, hInstance is a DWORD that will hold the application instance handle.
Start of code:
start:
; Get module handle and save it
invoke GetModuleHandle, NULL
mov hInstance, eax
; Init Common Controls library
invoke InitCommonControls
; Run winmain procedure and exit program
invoke WinMain, hInstance, NULL, NULL, SW_SHOWNORMAL
invoke ExitProcess,eax
GetModuleHandle retreives the module handle, which is stored in hInstance. InitCommonControls is an initialization function for the common control library. This library contains several controls that we will use in our program, and it should be initialized by calling InitCommonControls. After that, WinMain is called (a function we will create soon). WinMain will return when the user quits the program, whereafter ExitProcess is called to quit the process.
The WinMain procedure:
; WinMain
;==================================================================
WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:DWORD
LOCAL wc:WNDCLASSEX
LOCAL msg:MSG
LOCAL hwnd:HWND
mov wc.cbSize,SIZEOF WNDCLASSEX
mov wc.style, CS_HREDRAW or CS_VREDRAW
mov wc.lpfnWndProc, OFFSET WndProc
mov wc.cbClsExtra,NULL
mov wc.cbWndExtra,NULL
push hInstance
pop wc.hInstance
mov wc.hbrBackground,COLOR_WINDOW
mov wc.lpszMenuName, NULL
mov wc.lpszClassName,OFFSET ClassName
Here our icons are loaded from the resource file and their handles are stored in wc.hIcon and wc.hIconSm. Windows will use these handles to display the icons in the main window:
mov wc.hIcon, eax
invoke LoadIcon, hInstance, ICON2_SMALL
mov wc.hIconSm, eax
invoke LoadCursor,NULL,IDC_ARROW
mov wc.hCursor,eax
invoke RegisterClassEx, addr wc
INVOKE CreateWindowEx,NULL,ADDR ClassName,ADDR AppName,\
WS_OVERLAPPEDWINDOW-WS_MAXIMIZEBOX-WS_SIZEBOX,\
CW_USEDEFAULT, CW_USEDEFAULT,258,350,NULL,NULL,\
hInst,NULL
mov hwnd,eax
invoke ShowWindow, hwnd, CmdShow
invoke UpdateWindow, hwnd
.WHILE TRUE
invoke GetMessage, ADDR msg,NULL,0,0
.BREAK .IF (!eax)
invoke TranslateMessage, ADDR msg
invoke DispatchMessage, ADDR msg
.ENDW
mov eax,msg.wParam
ret
WinMain endp
The WinMain functions initializes a WNDCLASSEX structure that includes parameters of the windows class, then RegisterClassEx is called to register the window class named 'Mosaic32'. CreateWindowEx is called to create a new window based on the new class, ShowWindow and UpdateWindow will make the window visible. Then the program goes in an infinite loop until the user closes the window. This loop is called the message pump (see my tutorials for more info).
The window style is WS_OVERLAPPEDWINDOW without a Maximize-button and without a sizebox (=not resizeable). The window is 258x350 pixels.
The window also needs a window procedure that handles all the messages sent to the window. In our program this is the function WndProc, which takes 4 parameters: hWnd contains the window handle, uMsg the message, wParam and lParam the message parameters.
; Window procedure
;==================================================================
WndProc proc hWnd:DWORD, uMsg:DWORD, wParam:DWORD, lParam:DWORD
mov eax, uMsg
.IF eax==WM_CREATE
; yet to do
.ELSEIF eax==WM_DESTROY
invoke PostQuitMessage, NULL
.ELSE
invoke DefWindowProc,hWnd,uMsg,wParam,lParam
ret
.ENDIF
ret
WndProc endp
The window procedure processes the WM_DESTROY message to quit when the user quits.
After you've done all this, your files should look like this: mosaic1.zip
Now run make.bat to assemble & link your program. You should have no errors (you might get a warning about gdi32 but never mind about that) and you should be able to run the program. It has a small icon in the upper left corner, the big icon is visible in the task list (ALT+TAB) and your mosaic.exe has the big icon as icon.
