Today

1
Lecture 22

• Today
• OnPaint Some final Comments
• Bitmaps
• Reading
• Visual C manuals are online
• http//msdn.microsoft.com/library
• The MFC book finish reading
• Ready for a surprise reading quiz on Thursday?
• Assignment
• Project 5 due Nov. 12 (9pm)

2
OnPaint

• Call OnPaint indirectly through one of these
  methods
• Invalidate(BOOL eraseTRUE)
• InvalidateRect(CRect paintregion, BOOL erase)
• Calling Invalidate puts an invalidate message in
  the message queue. OnPaint will not be called
  immediately.
• Void SomeMethod()
• code
• InvalidateRect(region1)
• code
• InvalidateRect(region2)
• Results in one(1!) call to paint and its at
  some later time. The paint regions are
  magically merged.

3
3 useful CFrameWnd methods

• To find the size of the window
• GetWindowRect(CRect)
• CRect window_rect
• GetWindowRect(window_rect)
• //after this call, window_rect will contain the
  coordinates for the entire Window, these
  coordinates will be in relation to the edge of
  the entire screen including title bar and menu
• To find the size of the Client window (the white
  space)
• GetClientRect(CRect)
• CRect screen
• GetClientRect(screen) //
• To resize the window
• SetWindowPos(pointer, new-left, new-top, width,
  height, flags)
• SetWindowPos(NULL, 10, 10, 300, 200, 0)

4
Projects 5 6 - 7

• P5 CSWinKalah Due in two weeks.
• If you havent started youre behind schedule
• MFC is packed with surprises not a one day
  assignment
• Turn it in early and start on P6 early
• P6 CSWinKalahGold Due in 4 weeks.
• Same as P5 but with N (N to be decided later)
  improvements
• You select the improvements Ill post a few
  ideas
• Animation is possible but may require redesigning
  Kalah. Well see some simple animation techniques
  in class soon.
• Will require a dialog details will be posted on
  assignment page closer to P5s deadline.
• P7 CSWinOriginal_Idea Due by semester end.
  Would like to see demonstrated in class. 100
  before last day of class. 90 Last day of class.
  80 Prior to final. 70 On final or thru email
  submission. Note All projects must still be
  submitted via email.
• It may be a good idea to check your idea with me.
  While I will grant great leeway. complexity
  equivalent to Tic-Tac-Toe will not be enough. Try
  to challenge yourself, yet work within your
  abilities.

5
Displaying graphics

• Can display bitmap (.bmp) files in window
• Basic concept
• Link a bitmap image to the program via the
  programs resource file
• Load the bitmap image into a memory image
• Whenever you re-paint the window, re-draw the
  image as part of the re-paint process

6
App that just displays an image

• Header file
• include ltafxwin.hgt
• class CPictureWnd public CFrameWnd
• public
• CPictureWnd()
• afx_msg void OnPaint()
• private
• CDC m_memDC
• DECLARE_MESSAGE_MAP( )

• Basic class declaration
• Will put our image out on the window, and then
  repaint it whenever necessary
• Data member
• m_memDC contains a copy of the image in memory

7
Application (part one)

• CPictureWndCPictureWnd() Create(NULL, "Image
  Demo", WS_OVERLAPPEDWINDOW, CRect(100,100,500,50
  0))
• CBitmap bmpPicture
• bmpPicture.LoadBitmap ("MY_PICTURE")CClientDC
  dc(this)m_memDC.CreateCompatibleDC (dc)
• m_memDC.SelectObject (bmpPicture)
• bmpPicture.DeleteObject()

• Constructor for the CPictureWin class
• Create the window
• Load in the picture into a bitmap image via
  LoadBitmap
• This bmpPicture may be used for multiple BitMaps
• Create compatible image in memory so that you can
  transfer the image in memory to the screen
• Store information about the bitmap into the CDC
• Release the current Bitmap in bmpPicture so you
  can create another one if you wish

8
Application (part two)

• afx_msg void CPictureWndOnPaint() CPaintDC
  dc(this)dc.BitBlt(50,50,120,100, m_memDC,
  0, 0, SRCCOPY)dc.BitBlt(200,200,120,100,
  m_memDC, 0, 0, SRCCOPY)
• BEGIN_MESSAGE_MAP (CPictureWnd, CFrameWnd)
• ON_WM_PAINT( )
• END_MESSAGE_MAP( )

• OnPaint routines redraws window, which includes
  the graphic image
• Draw two copies of the image, one starting at
  (50,50) and one starting at (200,200).
• Both draw what is in m_memDC
• SRCCOPY is a bit-by-bit copy option

9
Application (part three)

• class CPictureApp public CWinApp
• public
• BOOL InitInstance()
• m_pMainWnd new CPictureWnd
• m_pMainWnd-gtShowWindow (m_nCmdShow)
• m_pMainWnd-gtUpdateWindow()
• return TRUE
• pictureApp
• MY_PICT1 BITMAP "elephant.bmp"

• Standard driver portion, loads an instance of
  CPictureWin as the application
• Resource file shown on the left in red, only one
  line that identifies the bitmap file

10
Class Exercises

• Download Zip4
• Try out these 4 things
• Modify the code so that you can get as many
  elephants as possible in the window without any
  of them overlapping
• Involves multiple BitBlt statements in OnPaint
• Make a hollow square of elephants.
• Look for images on the internet to use in your
  application.
• Add multiple images think about using a CDC
  array in order to store information about how the
  images should be displayed on the screen.
• For multiple bitmaps, you only need multiple
  CDCs you may use one CBitmap instance to load
  the bitmaps as long as you call the
  CBitmapDeleteObject() method

11
Adding timers to our programs

• Timers allow certain events to happen at specific
  times
• Move things on a page
• Provide a finite time for the user to respond
• Simple example take our program from last time
  that displayed an elephant and move it around the
  page
• Change our header slightly
• Change our body (program)
• Same resource file

12
Header Resource File

• include ltafxwin.hgt
• class CPictureWnd public CFrameWnd
• public
• CPictureWnd()
• afx_msg void OnPaint()
• afx_msg void OnTimer()
• afx_msg void OnDestroy()
• private
• CDC m_memDC
• int x, y
• DECLARE_MESSAGE_MAP()
• MY_PICTURE BITMAP "elephant.bmp"

• Standard class header, now handle
• Repaints
• Timer
• Destroy (at end of program)
• Standard local variable
• Resource file doesnt change

13
Program body (part 1)

• include "pictureWnd.h"
• CPictureWndCPictureWnd()
• Create(NULL, "Image Example", WS_OVERLAPPEDWINDOW
  ,
• CRect(100,100,500,500))
• x 20 y 20
• CBitmap bmpPicture
• bmpPicture.LoadBitmap("MY_PICTURE")
• CClientDC dc(this)
• m_memDC.CreateCompatibleDC(dc)
• m_memDC.SelectObject(bmpPicture)
• afx_msg void CPictureWndOnDestroy()
  KillTimer(1)

• Constructor does not change from last time, loads
  image into memory
• New routine OnDestroy
• invoked when window exits
• shuts down timer (bad things happen to the OS if
  you forget this)

14
Program body (part 2)

• afx_msg void CPictureWndOnPaint() CPaintDC
  dc(this)dc.BitBlt(x,y,120,100, m_memDC, 0,
  0, SRCCOPY)
• afx_msg void CPictureWndOnTimer()
• bool z FALSE
• x10 if (x gt 200) x 20 z TRUE
• y10 if (y gt 200) y 20 z TRUE
• InvalidateRect(NULL, z)

• OnPaint
• draws image at the specified location
• OnTime occurs when timer event occurs
• increments x and y
• Forces call of OnPaint
• Second parameter indicates whether to erase
  current window or not

15
Program body (part 3)

• BEGIN_MESSAGE_MAP (CPictureWin,
  CFrameWnd)ON_WM_TIMER( )ON_WM_PAINT(
  )ON_WM_DESTROY( )
• END_MESSAGE_MAP()
• class CPictureApp public CWinApp
• public
• BOOL InitInstance() m_pMainWnd new
  CPictureWndm_pMainWnd-gtShowWindow(m_nCmdShow)m
  _pMainWnd-gtUpdateWindow()if (
  !m_pMainWnd-gtSetTimer(1,200,NULL) ) return
  FALSEreturn TRUE
• pictureApp

• Standard message map and CWinApp
• CWinApp now also starts the timer
• Identifier (ID)
• Timer goes off every 200 milliseconds
• Routine to handle timer events, NULL sends to
  current window

16
Class Exercises

• The program is out on the web at
• Zip6
• pictureWnd.h
• pictureWnd.cpp
• resource.rc
• elephant.bmp
• Modify the code so that your elephant moves in a
  square (clockwise) around your window
• Modify your code so that it
• Moves very fast
• Moves very slow

17
DoubleBuffering (Why isnt it automatic!)

• afx_msg void CKalahFrameWndOnPaint()
• //step 1 set up a buffer
• CPaintDC paintDC(this) CDC dbufdc
• dbufdc.CreateCompatibleDC(paintDC)
• CRect screen GetClientRect(screen)
• CBitmap bmp
• bmp.CreateCompatibleBitmap(
• paintDC, screen.Width(), screen.Height() )
• dbufdc.SelectObject(bmp)
• //step2 draw on dbbufdc
• dbbuddc.TextOut()
• dbbufdc.FillRect(CRect(x,y,xw, yh), pBrush)
• //step3 copy buffer to screen
• paintDC.BitBlt(0, 0, screen.Width(),
  screen.Height(),
• dbufdc, 0, 0, SRCCOPY )

18
Another example with timers

• Must complete a task within a specified amount of
  time
• Could use this to have a timed game.
• Our example program will simply count down a
  timer to zero
• We want to see if you can do 25 mouse clicks in
  10 seconds

19
Program header

• include ltafxwin.hgt
• class CTimeWin public CFrameWnd
• publicCTimeWin()afx_msg void OnLButtonDown
  (UINT, CPoint)afx_msg void OnPaint()afx_msg
  void OnTimer()afx_msg void OnDestroy()
• privateint m_nClicksint m_nTimeLeftCFont
  m_bigFontDECLARE_MESSAGE_MAP()

• Standard header file
• Handle
• Left button events
• OnPaint events
• OnTimer events
• OnDestroy events
• Class members
• Number of clicks
• Time left
• A font

20
Program body (part 1)

• include ltstrstrea.hgt
• include "main.h"
• CTimeWnd CTimeWnd()
• Create(NULL, "Timer and Text Example", WS_OVERLA
  PPEDWINDOW,CRect(100,100,500,500))m_nClicks
  25m_nTimeLeft 10m_bigFont.CreateFont
• (144,0,0,0,FW_BOLD,0,0,0,0,0,0,0,0,"Arial")Mess
  ageBox("Try to click the mouse 25 times in 10
  seconds", "Click Test")
• afx_msg void CTimeWnd OnDestroy()
  KillTimer(1)

• Standard constructor
• Set variables
• Define a font (size 144, bold, Arial)
• Pop up a message box letting them know what to do
  before the window opens

21
Program body (part 2)

• afx_msg void CTimeWnd OnPaint() CPaintDC
  dc(this)CFont pfont dc.SelectObject(m_bigFo
  nt)ostrstream ss ltlt m_nTimeLeftltlt '\0'CRect
  rectGetClientRect(rect)int midX
  (rect.right / 2) -36strlen(arText)int midY
  (rect.bottom / 2) - 72dc.SetTextColor(RGB(255,0,
  0))dc.TextOut(midX,midY, arText)

• Paint routine, writes the current time left (in
  seconds) using our specified font
• Allocate a font
• Put text in array
• Get size of our current window
• Calculate middle
• Write the info using our font, centering it on
  the screen

22
Program body (part 3)

• afx_msg void CTimeWnd OnTimer() if
  (m_nTimeLeft 0) KillTimer(1)
  MessageBox("Too Slow", "Click Test")
  SendMessage(WM_CLOSE)else
  InvalidateRect(NULL) m_nTimeLeft--
• afx_msg void CTimeWnd OnLButtonDown (UINT a,
  CPoint p) m_nClicks--if (m_nClicks0)
  KillTimer(1)MessageBox("Success", "Click
  Test")

• Timer routine
• If reach zero, print message and close
• Else redraw our window and decrement the counter
• Button routine
• Decrement clicks left
• If at zero, kill timer (done)

23
Program body (part 4)

• BEGIN_MESSAGE_MAP (CTimeWnd, CFrameWnd)ON_WM_LB
  UTTONDOWN()ON_WM_TIMER()ON_WM_PAINT()ON_WM_DEST
  ROY()
• END_MESSAGE_MAP()
• class CTimeApp public CWinApp
• publicBOOL InitInstance() m_pMainWnd new
  CTimeWndm_pMainWnd-gtShowWindow(m_nCmdShow)m_pM
  ainWnd-gtUpdateWindow()if ( !m_pMainWnd-gtSetTimer
  (1,1000,NULL) ) return FALSEreturn TRUE
• timeApp

• Standard message map
• Standard application framework
• Create window
• Start timer

24
Class Exercises

• The timer routine is out on the web
• Zip11
• main.h
• main.cpp
• Experiment 1
• Comment out CreateFont line in the constructor
  and regenerate it watch how VC prompts you
• Change the font size, change some other options
• Look up CreateFont in the help for complete
  info
• Experiment 2 Re-write this program so it tells
  how many clicks you can do in 10 secs

25
Capturing text typed in window

• Basic idea is you want to capture keystrokes that
  are made within the window
• Simple example
• Capture keystrokes in the window
• Just display the keys entered
• Must worry about newlines and backspace keys
• Basic assumptions for this example
• Wont ever type more than 32 lines of 80
  characters each

26
Program Header

• include ltafxwin.hgt
• class CTextInputWin public CFrameWnd
• public
• CTextInputWin()afx_msg void OnPaint()afx_msg
  void OnChar (UINT, UINT, UINT)
• privatechar m_arText3280int m_iRowint
  m_iLengthDECLARE_MESSAGE_MAP( )

• Class declaration
• OnChar routine has three arguments
• Character
• Repeat factor
• Flags
• Private data
• Array of info typed
• Current row
• Current position in row

27
Program Body (part 1)

• include "main.h"
• CTextInputWinCTextInputWin()
• Create(NULL, "Text Input Example",
  WS_OVERLAPPEDWINDOW,
• CRect(100,100,500,500))
• m_iRow 0
• m_iLength 0
• m_arText00 '\0'
• afx_msg void CTextInputWinOnPaint()CPaintDC
  dc(this)for (int a0 altm_Row a)
  dc.TextOut(10, 2015a, m_arTexta)

• Constructor
• Build window
• Set up local variables (first row, first column,
  null terminated)
• OnPaint simply re-writes all the characters in
  our array, one line at a time
• Each row is offset

28
Program Body (part 1)

• afx_msg void CTextInputWinOnChar (UINT ch, UINT
  repeat, UINT flags)
• switch (ch) case '\r' m_arTextm_Rowm_Le
  ngth '\0' m_Row m_arTextm_Row0
  '\0' m_Length 0 breakcase '\b'
  if (m_Length gt 0) m_Length--
  breakdefault m_arTextm_Rowm_Lengthch
  m_arTextm_Rowm_Length
  '\0'InvalidateRect(NULL,)

• Process a char
• Switch on type of character
• Newline, move to next row in array
• Backspace, reset length of line
• Normal char, add it to the line and mark the next
  position as the end
• Repaint window

29
Program Body (part 3)

• BEGIN_MESSAGE_MAP (CTextInputWin,
  CFrameWnd)ON_WM_PAINT( )ON_WM_CHAR( )
• END_MESSAGE_MAP( )
• class CTextInputApp public CWinApp
• public
• BOOL InitInstance() m_pMainWnd new
  CTextInputWinm_pMainWnd-gt ShowWindow(m_nCmdShow
  )m_pMainWnd-gtUpdateWindow()return TRUE
• textApp

• Message map handles character events and window
  repaints
• Standard driver

30
Class Exercises

• Download the example from class
• Zip8
• Run the program.
• Does a line of 79 characters or more wrap?
• Does backspace erase characters or just logically
  remove them?
• Can you backspace up multiple lines?
• How would you fix your program to backspace up
  multiple lines?
• What happens if you type more than 32 lines or if
  you backspace when there is nothing there

31
Dialog Boxes

• Can include both check boxes and radio
  buttons in a dialog box
• Check boxes have two states
• Checked
• Not checked
• Radio buttons have a number of alternatives
• Only one alternative may be selected

32
Adding check boxes

• Processing the button
• CButton pButton1 (CButton )
  GetDlgItem(IDC_ID1)
• CButton pButton2 (CButton )
  GetDlgItem(IDC_ID2)
• if ( pButton1-gtGetCheck( ) )
• MessageBox(ID1 Checked", "old")
• else
• MessageBox(ID1 Not Checked", "old")
• if ( pButton2-gtGetCheck( ) )

• Add to rc file
• MyDialog DIALOG 20,20,100,100
• CAPTION Some Caption
• LTEXT
• EDITTEXT
• DEFPUSHBUTTON
• AUTOCHECKBOX "New,
• IDC_ID1, 65, 10, 30, 20
• AUTOCHECKBOX "Old, IDC_ID2, 65, 40, 30, 20
• Add identifiers to identifiers.h file

33
Adding Radio Buttons

• Code in your routines
• int ans GetCheckedRadioButton (IDM_A, IDM_C)
• switch (ans)
• case IDM_A MessageBox ("selected option A",
  "select") break
• case IDM_B MessageBox ("selected option B",
  "select") break
• case IDM_C MessageBox ("selected option C",
  "select") break

• Resource File
• GROUPBOX "A B C" , IDM_RADIO,100,100,60,60
• AUTORADIOBUTTON "A", IDM_A, 120, 120, 10, 10
• AUTORADIOBUTTON "B", IDM_B, 130, 130, 10, 10
• AUTORADIOBUTTON "C", IDM_C, 140, 140, 10, 10
• Groupbox (above) outlines the set of radio
  buttons
• Code (other side) retrieves the checked option
  (within range of IDM_A to IDM_C)

34
Class Exercises

• Zip 9
• Add two more option buttons (options 3 4)
• Move the OK button down to the bottom of the
  dialog box, and make it square
• Add two more radio buttons, line all up
  vertically
• Make sure you can separate functionality and what
  methods perform what events.
• Check out and play around with
• SetWindowPos(NULL, 10, 10, 300, 200, 0)