Today

1
Lecture 20

• Today
• Timers
• Capturing Text
• Radio buttons
• Go ahead and get started
• Fire up Dev Studio when you get logged on
• Download the files for the first class exercise
• Announcements
• Project 4 due Nov 6

2
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

3
Header Resource File

• include
• 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

4
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

5
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 200) x 20 z TRUE
• y10 if (y 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

6
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-ShowWindow(m_nCmdShow)m
  _pMainWnd-UpdateWindow()if (
  !m_pMainWnd-SetTimer(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

7
Class Exercises

• The program is out on the web at
• Zip1
• 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

8
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

9
Program Header

• include
• 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

10
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 adc.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

11
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 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

12
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- ShowWindow(m_nCmdShow
  )m_pMainWnd-UpdateWindow()return TRUE
• textApp

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

13
Class Exercises

• Download the example from class
• Zip2
• 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

14
3 CFrameWnd methods

• To find the size of the window
• GetWindowRect(LPRECT ( coordinates stored as
  usual CRect coordinates))
• CRect what
• GetWindowRect(what)
• //after this call, what will contain the
  coordinates for the entire Window, these
  coordinates will be in relation to the edge of
  the entire screen
• To find the size of the Client window (the white
  space)
• GetClientRect(LPRECT)
• CRect what
• GetClientRect(what) // what is same as above
• To resize the window
• SetWindowPos(pointer, new-left, new-top, width,
  height, flags)
• SetWindowPos(NULL, 10, 10, 300, 200, 0)

15
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

16
Adding check boxes

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

• 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

17
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)

18
Class Exercises

• Zip3
• 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)

19
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

20
Program header

• include
• 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

21
Program body (part 1)

• include
• 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

22
Program body (part 2)

• afx_msg void CTimeWnd OnPaint() CPaintDC
  dc(this)CFont pfont dc.SelectObject(m_bigFo
  nt)ostrstream ss 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

23
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)

24
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-ShowWindow(m_nCmdShow)m_pM
  ainWnd-UpdateWindow()if ( !m_pMainWnd-SetTimer
  (1,1000,NULL) ) return FALSEreturn TRUE
• timeApp

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

25
Class Exercises

• Option One
• The timer routine is out on the web
• Zip4
• 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