TweetFollow Us on Twitter

Window Related Events
Volume Number:9
Issue Number:1
Column Tag:Getting Started

Related Info: Event Manager Window Manager

Window Related Events

Handling update, activate and suspend/resume events

By Dave Mark, MacTech Magazine Regular Contributing Author

Note: Source code files accompanying this article are located on MacTech CD-ROM or source code disks.

In last month’s column, we covered the basics of event loop programming, focusing on four specific events: the mouseDown, mouseUp, keyDown, and autoKey events. If you haven’t already, be sure to read through the Event Manager chapters in Inside Macintosh, Volumes I and VI. Pay specific attention to the sections that describe the mouseDown, mouseUp, keyDown, and autoKey events in detail. Finally, go back to last month’s program and flesh it out a little. When a mouseDown occurs, draw a string in the event window that describes where and when the mouseDown occurred. For a keyDown, draw the character and key codes embedded in the EventRecord.

In this month’s column, we’re going to expand our event handling repertoire, focusing on activate, update, and suspend/resume events.

Activate Events

Every time your application creates a window, that window is added to a list maintained by the Window Manager. The windows in this list are in the order that they appear on the screen, from the frontmost to the rearmost. The frontmost window is also known as the active window. In Figure 1, Window #1 starts off as the active window. Notice the difference between the title bars of the active and non-active window.

When the mouse is clicked in the rear window, Window #1 is made inactive, then the rear window, Window #2, is made active. Since the front window is made inactive before another window is brought to the front, there will never be more than one active window at a time!

The Window Manager accomplishes this by sending your application a series of activate events. If a rear window is being brought to the front, your application will receive two activate events. The first tells you that the frontmost window is becoming inactive. This event is also known as a deactivate event. The second event tells your application that a window is becoming active. Both of these events set EventRecord.what to activateEvt.

If a window is created, and there are no currently open windows, the Window Manager only generates a single activate event, indicating that the newly created window is becoming active. In this case, no deactivate event is sent.

Figure 1. A mouse click in Window #2 brings it to the front.

In general, you’ll use activate events if you treat window contents differently for an active window than for an inactive window. For example, your application might highlight selected text in the active window, but not in an inactive window. Activate events are provided for your benefit. Use them as you see fit. You’ll see how we discriminate between an activate and deactivate event when we get to our program later in the column.

Figure 2. When Window #1 is dragged to the left, more of Window #2 is exposed, causing an update event.

Update Events

Next on our list of events is an event that tells your program to update the contents of a window. The updateEvt is generated when a window is created (after the activateEvt is generated) and when a new portion of a window is revealed. Figure two shows a typical sequence that generates an updateEvt. The first picture shows Window #1 partially obscuring Window #2. Next, Window #1 is dragged to the left, revealing a previously hidden section of the Window #2. The Window Manager sends an updateEvt to your application, telling it to update the contents of Window #2. The third picture shows the window, after the program responded to the update event.

Figure 3 shows a slightly different sequence, involving update and activate events. This time, the mouse is clicked in Window #2, bringing it to the front. First, a deactivate event is generated for Window #1. Next, an activate event is generated for Window #2. Finally, an update event is generated, asking the program to update the contents of Window #2.

Once again, you’ll see update and activate events in action in the program later in the column.

Figure 3. When Window #2 is moved to the front, two activate events and an update event are generated.

Suspend/Resume Events

Under MultiFinder (System 6) and under System 7, more than one application is allowed to run at a time. When you click in a window belonging to a background application, the active application receives a suspend event, and the background application receives a resume event and is moved to the foreground.

You might use suspend and resume events to determine the actions taken by your program. For example, in the foreground, you might display a special tool palette, or perhaps run an animation. When your application moves into the background, you’ll receive a suspend event and you might hide the tool palette, or discontinue the animation until you get a resume event.

It’s important to note that your application can continue running, even if it receives a suspend event. It will still continue to receive update (and other appropriate events) while in the background. At the very least, it’s a good idea to treat a suspend event as you would a deactivate event when it comes to the contents of your windows. For example, if you usually deselect any selected text when a window is deactivated, do the same thing for the active window when you receive a suspend event.

At Last! The Program!

As promised, here’s a program that incorporates all the events described in this column. WindowMaster creates a single window and handles all the usual events relating to windows. Figure 4 shows the WindowMaster window in all its glory. Notice that this window sports a close box, a zoom box, a drag region (the title bar), and a grow box. Though this window doesn’t support scroll bars, there is room for them. In most cases, if a window has a grow box, it has room for scroll bars. We’ll get to scroll bars in a later column.

Figure 4. WindowMaster in action.

Creating the WindowMaster Resources

Create a folder in your development folder named WindowMaster. Launch ResEdit, then create a resource file named WindowMaster.Π.rsrc in your WindowMaster folder. You’ll create two resources in this file.

First, create a WIND resource according to the specifications in Figure 5. Next, select Set 'WIND' Characteristics... from the WIND menu and set the window’s title to PICT 128. Next, copy a graphic from your scrapbook into the clipboard. If you don’t have anything interesting in your scrapbook, go draw something. I’ll wait.

Figure 5. Specifications for WindowMaster’s WIND resource.

Once you’ve got a graphic in the clipboard, return to ResEdit and select Paste from the Edit menu. ResEdit will place your picture in a PICT resource. Make sure the PICT resource has a resource ID of 128. Well, that’s it for ResEdit. Quit, making sure you save your changes.

Creating the WindowMaster Project

Once you’re out of ResEdit, launch THINK C and create a new project file named WindowMaster.Π in the WindowMaster folder. Add MacTraps to the project file. Next, select New from the File menu and type this source code into the window that appears.

/* 1 */
#include <Values.h>

#define kBaseResID 128
#define kMoveToFront (WindowPtr)-1L
#define kSleep   MAXLONG

#define kScrollBarAdjust  (16-1)
#define kLeaveWhereItIs   false
#define kNormalUpdates    true

#define kMinWindowHeight  50
#define kMinWindowWidth   80

/*************/
/*  Globals  */
/*************/

Boolean gDone;

/***************/
/*  Functions  */
/***************/

void  ToolBoxInit( void );
void  WindowInit( void );
void  EventLoop( void );
void  DoEvent( EventRecord *eventPtr );
void  HandleMouseDown( EventRecord *eventPtr );
void  DoUpdate( EventRecord *eventPtr );
void  DoPicture( WindowPtr window, PicHandle picture );
void  DoActivate( WindowPtr window, Boolean becomingActive );
void  DoSuspendResume( Boolean resuming );
void  CenterPict( PicHandle picture, Rect *srcRectPtr,
 Rect *destRectPtr );


/******************************** main *********/

void  main( void )
{
 ToolBoxInit();
 WindowInit();
 
 EventLoop();
}

/*********************************** ToolBoxInit */

void  ToolBoxInit( void )
{
 InitGraf( &thePort );
 InitFonts();
 InitWindows();
 InitMenus();
 TEInit();
 InitDialogs( nil );
 InitCursor();
}

/******************************** WindowInit *********/

void  WindowInit( void )
{
 WindowPtrwindow;
 
 window = GetNewWindow( kBaseResID, nil, kMoveToFront );
 
 if ( window == nil )
 {
 SysBeep( 10 );  /*  Couldn't load the WIND resource!!!  */
 ExitToShell();
 }
 
 ShowWindow( window );
 SetPort( window );
}
/******************************** EventLoop *********/

void  EventLoop( void )
{
 EventRecordevent;
 
 gDone = false;
 while ( gDone == false )
 {
 if ( WaitNextEvent( everyEvent, &event, kSleep, nil ) )
 DoEvent( &event );
 }
}

/************************************* DoEvent      */

void  DoEvent( EventRecord *eventPtr )
{
 BooleanbecomingActive, resuming;
 
 switch ( eventPtr->what )
 {
 case mouseDown: 
 HandleMouseDown( eventPtr );
 break;
 case updateEvt:
 DoUpdate( eventPtr );
 break;
 case activateEvt:
 becomingActive = ( (eventPtr->modifiers & activeFlag)
 == activeFlag );
 DoActivate( (WindowPtr)eventPtr->message, 
 becomingActive );
 break;
 case osEvt:
 resuming = ( eventPtr->message & suspendResumeMessage )
 == resumeFlag;
 DoSuspendResume( resuming );
 break;
 }
}

/************************************* HandleMouseDown */

void  HandleMouseDown( EventRecord *eventPtr )
{
 WindowPtrwindow;
 short  thePart;
 GrafPtroldPort;
 long   windSize;
 Rect   growRect;
 
 thePart = FindWindow( eventPtr->where, &window );
 
 switch ( thePart )
 {
 case inSysWindow : 
 SystemClick( eventPtr, window );
 break;
 case inContent:
 SelectWindow( window );
 break;
 case inDrag : 
 DragWindow( window, eventPtr->where, 
 &screenBits.bounds );
 break;
 case inGoAway :
 if ( TrackGoAway( window, eventPtr->where ) )
 gDone = true;
 break;
 case inGrow:
 growRect.top = kMinWindowHeight;
 growRect.left = kMinWindowWidth;
 growRect.bottom = MAXSHORT;
 growRect.right = MAXSHORT;
 
 windSize = GrowWindow( window, eventPtr->where, 
 &growRect );
 if ( windSize != 0 )
 {
 GetPort( &oldPort );
 SetPort( window );
 EraseRect( &window->portRect );
 SizeWindow( window, LoWord( windSize ),
 HiWord( windSize ), kNormalUpdates );
 InvalRect( &window->portRect );
 SetPort( oldPort );
 }
 break;
 case inZoomIn:
 case inZoomOut:
 if ( TrackBox( window, eventPtr->where, thePart ) )
 {
 GetPort( &oldPort );
 SetPort( window );
 EraseRect( &window->portRect );
 ZoomWindow( window, thePart, kLeaveWhereItIs );
 InvalRect( &window->portRect );
 SetPort( oldPort );
 }
 break;
 }
}

/************************************* DoUpdate     */

void  DoUpdate( EventRecord *eventPtr )
{
 short  pictureID;
 PicHandlepicture;
 WindowPtrwindow;
 
 window = (WindowPtr)eventPtr->message;
 
 BeginUpdate( window );
 
 picture = GetPicture( kBaseResID );
 
 if ( picture == nil )
 {
 SysBeep( 10 );  /*  Couldn't load the PICT resource!!!  */
 ExitToShell();
 }
 
 DoPicture( window, picture );
 
 EndUpdate( window );
}

/******************************** DoPicture *********/

void  DoPicture( WindowPtr window, PicHandle picture )
{
 Rect   drawingClipRect, destRect;
 RgnHandletempRgn;
 
 SetPort( window );
 
 EraseRect( &window->portRect );
 
 tempRgn = NewRgn();
 GetClip( tempRgn );

 drawingClipRect = window->portRect;
 drawingClipRect.right -= kScrollBarAdjust;
 drawingClipRect.bottom -= kScrollBarAdjust;
 
 ClipRect( &drawingClipRect );
 
 CenterPict( picture, &drawingClipRect, &destRect );
 DrawPicture( picture, &destRect );
 
 SetClip( tempRgn );
 DisposeRgn( tempRgn );
 
 DrawGrowIcon( window );
}

/************************************* DoActivate   */



void  DoActivate( WindowPtr window, Boolean becomingActive )
{
 DrawGrowIcon( window );
}

/************************************* DoSuspendResume    */

void  DoSuspendResume( Boolean resuming )
{
 WindowPtrwindow;
 
 window = FrontWindow();
 
 DrawGrowIcon( window );
}

/****************** CenterPict ********************/

void  CenterPict( PicHandle picture, Rect *srcRectPtr,
 Rect *destRectPtr )
{
 Rect pictRect;
 
 pictRect = (**( picture )).picFrame;
 
 OffsetRect( &pictRect, srcRectPtr->left - pictRect.left,
    srcRectPtr->top - pictRect.top);
 OffsetRect( &pictRect,
 (srcRectPtr->right - pictRect.right)/2,
 (srcRectPtr->bottom - pictRect.bottom)/2);
 
 *destRectPtr = pictRect;
}

Once your code is typed in, save it under the name WindowMaster.c, then add the window to the project by selecting Add from the Project menu.

Running WindowMaster

Select Run from the Project menu to run WindowMaster. A single window, like the one shown in Figure 4 should appear. Click the mouse in the title bar and drag the window around on the screen. Next, click in the grow box and resize the window. Try making it tall and skinny, then short and fat. Notice that there is a limit to how small you can make the window. Next, click on the zoom box in the upper-right corner of the window. The window should expand to fill the main screen. Click the zoom-box again to return the window to its previous size.

Next, drag the window downwards, so it is halfway off the screen, obscuring part of the picture. Now drag it back up. The picture will be redrawn in full. Finally, click in the window’s close box to exit the program.

Walking Through the Source Code

Just like last month’s program, WindowMaster is based on an event loop architecture. Also, like last month’s column, the program starts off by including <Values.h> to get the constant MAXLONG, used for the #define kSleep. The #defines will be explained as they are used.

/* 2 */
#include <Values.h>

#define kBaseResID 128
#define kMoveToFront (WindowPtr)-1L
#define kSleep   MAXLONG

#define kScrollBarAdjust  (16-1)
#define kLeaveWhereItIs   false
#define kNormalUpdates    true

#define kMinWindowHeight  50
#define kMinWindowWidth   80

gDone is initialized to false, then set to true when a click occurs in the window’s close box. Note that this is not the way Mac applications normally exit, but we haven’t got to menus yet, so a click in the close box will have to do for now.

/* 3 */
Boolean gDone;

As always, the code includes prototypes for all functions.

/* 4 */
void  ToolBoxInit( void );
void  WindowInit( void );
void  EventLoop( void );
void  DoEvent( EventRecord *eventPtr );
void  HandleMouseDown( EventRecord *eventPtr );
void  DoUpdate( EventRecord *eventPtr );
void  DoPicture( WindowPtr window, PicHandle picture );
void  DoActivate( WindowPtr window, Boolean becomingActive );
void  DoSuspendResume( Boolean resuming );
void  CenterPict( PicHandle picture, Rect *srcRectPtr,
 Rect *destRectPtr );

main() initializes the Toolbox, creates a window, then enters the main event loop.

/* 5*/
/******************************** main *********/

void  main( void )
{
 ToolBoxInit();
 WindowInit();
 
 EventLoop();
}

ToolBoxInit() is the same as it ever was.

/* 6 */
/*********************************** ToolBoxInit */

void  ToolBoxInit( void )
{
 InitGraf( &thePort );
 InitFonts();
 InitWindows();
 InitMenus();
 TEInit();
 InitDialogs( nil );
 InitCursor();
}

WindowInit() calls GetNewWindow() to load the WIND resource from the resource file.

/* 7 */
/******************************** WindowInit *********/

void  WindowInit( void )
{
 WindowPtrwindow;
 
 window = GetNewWindow( kBaseResID, nil, kMoveToFront );

If the resource wasn’t found, beep once, then exit.

/* 8 */
 if ( window == nil )
 {
 SysBeep( 10 );  /*  Couldn't load the WIND resource!!!  */
 ExitToShell();
 }

Once the window is created, make it visible, then make it the current port. Notice that this routine does not do any drawing. We’ll draw our picture in response to an update event.

/* 9 */
 ShowWindow( window );
 SetPort( window );
}

EventLoop() sets gDone to false, then loops around a call to WaitNextEvent(). If WaitNextEvent() returns true, the event is passed to DoEvent().

/* 10 */
/******************************** EventLoop *********/

void  EventLoop( void )
{
 EventRecordevent;
 
 gDone = false;
 while ( gDone == false )
 {
 if ( WaitNextEvent( everyEvent, &event, kSleep, nil ) )
 DoEvent( &event );
 }
}
DoEvent() switches on the event’s what field.

/************************************* DoEvent      */

void  DoEvent( EventRecord *eventPtr )
{
 BooleanbecomingActive, resuming;
 
 switch ( eventPtr->what )
 {

A mouseDown event is passed to HandleMouseDown(). An updateEvt is passed on to DoUpdate().

/* 11 */
 case mouseDown: 
 HandleMouseDown( eventPtr );
 break;
 case updateEvt:
 DoUpdate( eventPtr );
 break;

In the case of an activate event, the event’s modifiers field holds the key to whether the event is an activate or deactivate event. activeFlag is a mask that designates one of the bits in the modifiers field. If the bit is set, the event is an activate event. If the bit is clear, the event is a deactivate event. The Boolean becomingActive is true if the event is an activate event. Once becomingActive is set, it is passed on to DoActivate(). The event’s message field holds a pointer to the window being activated or deactivated.

/* 12 */
 case activateEvt:
 becomingActive = ( (eventPtr->modifiers & activeFlag)
 == activeFlag );
 DoActivate( (WindowPtr)eventPtr->message,
 becomingActive );
 break;

Similarly, an osEvt is used to indicate either a suspend or resume event. suspendResumeMessage is a predefined constant that designates the suspend/resume bit in the message field. resuming is set to true if the event is a resume event. Once set, resuming is passed on to DoSuspendResume().

/* 13 */
 case osEvt:
 resuming = ( eventPtr->message & suspendResumeMessage )
 == resumeFlag;
 DoSuspendResume( resuming );
 break;
 }
}

HandleMouseDown() handles the mouseDown event.

/* 14 */
/************************************* HandleMouseDown */

void  HandleMouseDown( EventRecord *eventPtr )
{
 WindowPtrwindow;
 short  thePart;
 GrafPtroldPort;
 long   windSize;
 Rect   growRect;

FindWindow() takes the event’s where field and returns the window at those coordinates. thePart indicates the part of the window the mouse click occurred in.

/* 15 */
 thePart = FindWindow( eventPtr->where, &window );

If the click was in a portion of the screen not belonging to our application (like a desk accessory window), thePart is set to inSysWindow and we’ll pass the event back to the system with SystemClick().

/* 16 */
 switch ( thePart )
 {
 case inSysWindow : 
 SystemClick( eventPtr, window );
 break;

If the event was in the content region of the window, we’ll typically call SelectWindow() to bring the window to the front. Since we only have one window, this line isn’t particularly useful. Later on though, you’ll add another window to this program and you’ll want to keep this code in here.

As your windows get more complex, you’ll want to do more with inContent clicks than just select the window. You might have a button or scroll bar in the window that needs action, or you might have some text that needs selection. This is the jumping off point for all clicks that occur in the window. Eventually, we’ll add a routine named DoContentClick() to process clicks in a window’s content region.

/* 17 */
 case inContent:
 SelectWindow( window );
 break;

If the click was in the window’s drag region (title bar), we’ll pass the window (retrieved by FindWindow()), and the mouse click coordinates to the Toolbox routine DragWindow(). The third parameter is a bounding rectangle that determines where on the screen the window may be dragged. screenBits.bounds is a System global variable that defines the boundaries of the main display.

If you have two monitors, this code works fine, however. DragWindow() checks for screenBits.bounds as a parameter and, if it finds it, allows dragging anywhere on any monitor attached to the system.

/* 18 */
 case inDrag : 
 DragWindow( window, eventPtr->where, 
 &screenBits.bounds );
 break;

If the mouseDown was in the close box, we’ll call TrackGoAway() to see if the mouse was released while still inside the close box. If so, gDone is set to true. TrackGoAway() is the routine that does the little animation in the close box.

/* 19 */
 case inGoAway :
 if ( TrackGoAway( window, eventPtr->where ) )
 gDone = true;
 break;

If the click was in the grow box, we set up a rectangle that defines how large and how small the window is allowed to grow [See Inside Macintosh, Vol. 1 - Tech Ed.]. Basically, it’s good policy to put a limit on how small a window can get, but, unless you’ve got a pressing reason, you should allow windows to get as large as the user wants.

/* 20 */
 case inGrow:
 growRect.top = kMinWindowHeight;
 growRect.left = kMinWindowWidth;
 growRect.bottom = MAXSHORT;
 growRect.right = MAXSHORT;

Next, this rectangle is passed on to GrowWindow(), which tracks the mouse, allowing the user to specify the new window size.

/* 21 */
 windSize = GrowWindow( window, eventPtr->where, &growRect );

The return value contains two 2-byte values, indicating the new height and width of the window [Both zero means no change - Tech Ed.].

/* 22 */
 if ( windSize != 0 )
 {

First, we’ll save away the current port (in case it’s not this window), then make this window the current port. Next, we erase the entire window and change the window’s size by calling SizeWindow(). The last parameter tells the system we want this resizing to generate an update event.

/* 23 */
 GetPort( &oldPort );
 SetPort( window );
 EraseRect( &window->portRect );
 SizeWindow( window, LoWord( windSize ),
 HiWord( windSize ), kNormalUpdates );

Next, we call InvalRect() to tell the system that the entire window should be redrawn with the next update event, not just the new area revealed by the grow box. In fact, this call will force an update even if the window was shrunk.

/* 24 */
 InvalRect( &window->portRect );

Because we center our picture in the window, we need to redraw the window contents whenever the window changes size. To see why this is true, try commenting out the previous line of code.

Update events are tricky. It is definitely worth reading the section of Inside Macintosh that covers the Window Manager. You might also check out Chapter 4’s Updater program in Volume I of the Mac Primer.

Once the window is resized, the port is set back to its old value. Since InvalRect() applies to the current port, it was important that we make the window being grown the current port.

/* 25 */
 SetPort( oldPort );
 }
 break;

Finally, a click in the zoom box follows a similar strategy. Again, TrackBox() is called to verify that the mouse was released inside the zoom box. If so, ZoomWindow() is called to zoom the window, or return it to its old position, depending on its current state.

/* 26 */
 case inZoomIn:
 case inZoomOut:
 if ( TrackBox( window, eventPtr->where, thePart ) )
 {
 GetPort( &oldPort );
 SetPort( window );
 EraseRect( &window->portRect );
 ZoomWindow( window, thePart, kLeaveWhereItIs );
 InvalRect( &window->portRect );
 SetPort( oldPort );
 }
 break;
 }
}

DoUpdate() is called whenever an update event occurs. First, the window is retrieved from the event’s message field. Next, BeginUpdate() is called, telling the Window Manager that we’re handling updates for this window. BeginUpdate() will restrict drawing to the region of the window that needs updating, also known as the update region. If you call InvalRect() on the whole window, the whole window is available for drawing.

/* 27 */
/************************************* DoUpdate     */

void  DoUpdate( EventRecord *eventPtr )
{
 short  pictureID;
 PicHandlepicture;
 WindowPtrwindow;
 
 window = (WindowPtr)eventPtr->message;
 
 BeginUpdate( window );

Next, we load the picture and pass it on to DoPicture().

/* 28 */
 picture = GetPicture( kBaseResID );
 
 if ( picture == nil )
 {
 SysBeep( 10 );  /*  Couldn't load the PICT resource!!!  */
 ExitToShell();
 }
 
 DoPicture( window, picture );
 
 EndUpdate( window );
}

DoPicture() makes the window the current port, then erases the entire window. Note that this will already have been done if the update event was caused by a resize or zoom, but there’s no harm in this minor duplication of code.

/* 29 */

/******************************** DoPicture *********/

void  DoPicture( WindowPtr window, PicHandle picture )
{
 Rect   drawingClipRect, destRect;
 RgnHandletempRgn;
 
 SetPort( window );
 
 EraseRect( &window->portRect );

Next, a new region is created. We pass this region handle on to GetClip(), which places a copy of the window’s clipping region in tempRgn. The clipping region defines which parts of the window can be drawn in and which parts can’t. Again, it is a good idea to read the entire Window Manager chapter in Inside Macintosh, as there’s not enough space to cover all of it in this column.

/* 30 */
 tempRgn = NewRgn();
 GetClip( tempRgn );

Since we want to center the picture in the part of the window not covered by the grow region and scroll bar areas, we’ll subtract those areas from the window’s portRect. Next, we’ll pass this rectangle on to ClipRect() making it the new clip region.

/* 31 */
 drawingClipRect = window->portRect;
 drawingClipRect.right -= kScrollBarAdjust;
 drawingClipRect.bottom -= kScrollBarAdjust;
 
 ClipRect( &drawingClipRect );

Next, we’ll call CenterPict() to center the picture in drawingClipRect, returning the rectangle the picture should be drawn in as its third parameter. We then draw the picture with DrawPicture().

/* 32 */
 CenterPict( picture, &drawingClipRect, &destRect );
 DrawPicture( picture, &destRect );

Next, the clipping region is set back to its old value and the grow icon is redrawn, completing our update.

/* 33 */
 SetClip( tempRgn );
 DisposeRgn( tempRgn );
 
 DrawGrowIcon( window );
}

It’s important to remember that your application can receive update events even if it’s running in the background. If a foreground application’s window covers your application’s windows and is then moved, the Window Manager will send your application update events asking you to redraw the effected windows.

DoActivate() is pretty simple. It redraws the grow icon in the specified window. DrawGrowIcon() will draw a different grow icon, depending on whether your window is frontmost or not. When your application starts handling more than one window, you’ll start making use of the second parameter, becomingActive.

/* 34 */

/************************************* DoActivate   */

void  DoActivate( WindowPtr window, Boolean becomingActive )
{
 DrawGrowIcon( window );
}

DoSuspendResume() is also pretty simple. This time the frontmost window’s grow icon is redrawn. A front window, which has been suspended gets the same grow icon as any other window. DrawGrowIcon() is smart enough to know the state of your application.

Once again, as your programs get more complex, you’ll make use of the second parameter, resuming.

/* 35 */
/************************************* DoSuspendResume    */

void  DoSuspendResume( Boolean resuming )
{
 WindowPtrwindow;
 
 window = FrontWindow();
 
 DrawGrowIcon( window );
}

CenterPict() centers the picture in the rectangle pointed to by srcRectPtr, returning the result in the rectangle pointed to by destRectPtr.


/* 36 */
/****************** CenterPict ********************/

void  CenterPict( PicHandle picture, Rect *srcRectPtr,
 Rect *destRectPtr )
{
 Rect pictRect;
 
 pictRect = (**( picture )).picFrame;
 
 OffsetRect( &pictRect, srcRectPtr->left - pictRect.left,
    srcRectPtr->top - pictRect.top);
 OffsetRect( &pictRect,
 (srcRectPtr->right - pictRect.right)/2,
 (srcRectPtr->bottom - pictRect.bottom)/2);
   
 *destRectPtr = pictRect;
}

Till Next Month

There’s a lot going on in this program. As I’ve said before, do yourself a favor and read the Window Manager chapter in Inside Macintosh. If a concept in this program seems fuzzy, try commenting out some of the code to see what happens. This is especially useful with the code that effects or handles update events. You might also try commenting out the calls to DrawGrowIcon() just to see what happens.

Finally, try adding another window to the program. Add a second WIND and a second PICT resource to the resource file, then create the new window in WindowInit(). You’ll be amazed how easy it is to add a second window. Go ahead, try it!

By the way, you may have noticed that this month’s program comes in C only. Sorry Pascal fans, but the programs (and this column) are just getting too big and I had to choose one language or the other. Hopefully, you now have enough examples of C and Pascal that you’ll be able to either come up to speed on C (my preference) or translate the code to Pascal yourself.

By the way, for those of you following Daniel’s career, he’s getting big (would you believe he’s already 16 pounds, and he’s only 12 weeks old!), and he smiles an awful lot. Till next month, keep programming and Happy Holidays!!!

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

PopChar 7.1 - Floating window shows avai...
We're also selling a 5-license family pack for only $25.99! PopChar helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to... Read more
BBEdit 11.1.1 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Picasa 3.9.139 - Organize, edit, and sha...
Picasa and Picasa Web Albums allows you to organize, edit, and upload your photos to the Web from your computer in quick, simple steps. Arrange your photos into folders and albums and erase their... Read more
Mac DVDRipper Pro 5.0.5 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
NetShade 6.2 - Browse privately using an...
This promotion is for NetShade and 1 year of Proxy and VPN services NetShade is an anonymous proxy and VPN app+service for Mac. Unblock your Internet through NetShade's high-speed proxy and VPN... Read more
CrossOver 14.1.3 - Run Windows apps on y...
CrossOver can get your Windows productivity applications and PC games up and running on your Mac quickly and easily. CrossOver runs the Windows software that you need on Mac at home, in the office,... Read more
Little Snitch 3.5.3 - Alerts you about o...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more
OmniGraffle Pro 6.2.3 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniFocus 2.2 - GTD task manager with iO...
OmniFocus helps you manage your tasks the way that you want, freeing you to focus your attention on the things that matter to you most. Capturing tasks and ideas is always a keyboard shortcut away in... Read more
1Password 5.3.2 - Powerful password mana...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more

MooVee - Your Movies Guru (Entertainmen...
MooVee - Your Movies Guru 1.0 Device: iOS iPhone Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: MooVee helps you effortlessly manage your movies, on your iPhone. | Read more »
Geometry Wars 3: Dimensions (Games)
Geometry Wars 3: Dimensions 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Enjoy the next chapter in the award-winning Geometry Wars franchise and enjoy stunning, console-quality... | Read more »
CHAOS RINGS Ⅲ (Games)
CHAOS RINGS Ⅲ 1.0.0 Device: iOS Universal Category: Games Price: $19.99, Version: 1.0.0 (iTunes) Description: The newest addition to the popular smartphone RPG series is finally here! ・CHAOS RINGS Overview | Read more »
The Popular Insight Series of Travel Gui...
Getting around in a country when you can't understand the primary language can be tough. Fortunately there are several options available to help wold travellers with the important stuff like giving directions to a cab driver or asking where the... | Read more »
Desktop Dungeons is Now on the iPad Desp...
Desktop Dungeons has been a well-loved roguelike on PC for quite some time, and now it's finally available for the iPad! Just the iPad, though. Sorry iPhone users. [Read more] | Read more »
Moleskine Timepage – Calendar for iCloud...
Moleskine Timepage – Calendar for iCloud, Google & Exchange 1.0 Device: iOS iPhone Category: Productivity Price: $4.99, Version: 1.0 (iTunes) Description: The most elegant calendar for your pocket and wrist, Timepage is a... | Read more »
QuizUp Gets Social in its New Update
Plain Vanilla Corp has released a new and improved version of their popular trivia game, QuizUp. The app now emphasizes social play so you can challenge friends from all over the world. [Read more] | Read more »
The Deep (Games)
The Deep 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Swipe Controls Delve into the deep in this retro rogue-like! Swipe to move your diver around and keep away from the enemies as you... | Read more »
Sproggiwood (Games)
Sproggiwood 1.2.8 Device: iOS Universal Category: Games Price: $9.99, Version: 1.2.8 (iTunes) Description: Sproggiwood was developed for devices with at least 1GB of RAM. We recommend you only download Sproggiwood if your device... | Read more »
Battle of Gods: Ascension (Games)
Battle of Gods: Ascension 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: TURN-BASED TACTICAL COMBATFight tactical battles against the forces of Hades! In Battle of Gods: Ascension you play... | Read more »

Price Scanner via MacPrices.net

Apple refurbished 2014 13-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and... Read more
What Would the ideal Apple Productivity Platf...
For the past four years I’ve kept a foot in both the Mac and iPad camps respectively. my daily computing hours divided about 50/50 between the two devices with remarkable consistency. However, there’... Read more
PageMeUp 1.2.1 Ten Dollar Page Layout Applica...
Paris, France-based Softobe, an OS X software development company, has announced that their PageMeUp v. 1.2.1, is available on the Mac App Store for $9.99. The license can be installed on up to 5... Read more
Eight New Products For USB Type-C Application...
Fresco Logic, specialists in advanced connectivity technologies and ICs, has introduced two new product families targeting the Type-C connector recently introduced across a number of consumer... Read more
Scripps National Spelling Bee Launches Buzzwo...
Scripps National Spelling Bee fans can monitor the action at the 2015 Spelling Bee with the new Buzzworthy app for iOS, Android and Windows mobile devices. The free Buzzworthy app provides friendly... Read more
13-inch 2.5GHz MacBook Pro on sale for $120 o...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $979 including free shipping plus NY sales tax only. Their price is $120 off MSRP, and it’s the lowest price for this model (except for Apple’... Read more
27-inch 3.3GHz 5K iMac on sale for $1899, $10...
B&H Photo has the new 27″ 3.3GHz 5K iMac on sale for $1899.99 including free shipping plus NY tax only. Their price is $100 off MSRP. Read more
Save up to $50 on iPad Air 2, NY tax only, fr...
B&H Photo has iPad Air 2s on sale for up to $50 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469 $30 off - 64GB iPad Air 2 WiFi: $549.99 $50 off - 128GB iPad... Read more
Updated Mac Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more
New 13-inch 2.9GHz Retina MacBook Pro on sale...
B&H Photo has the 13″ 2.9GHz/512GB Retina MacBook Pro on sale for $1699.99 including free shipping plus NY tax only. Their price is $100 off MSRP, and it’s the lowest price for this model from... Read more

Jobs Board

Program Manager, *Apple* Community Support...
**Job Summary** Apple Support Communities ( discussions. apple .com) helps customers get the most from their Apple products and services by providing access to Read more
Senior Data Scientist, *Apple* Retail - Onl...
**Job Summary** Apple Retail - Online sells Apple products to customers around the world. In addition to selling Apple products with unique services such as iPad Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Watch SW Application Project Manager...
**Job Summary** The Apple Watch software team is looking for an Application Engineering Project Manager to work on new projects for Apple . The successful candidate Read more
Engineering Manager for *Apple* Maps on the...
…the Maps App Team get to take part in just about any new feature in Apple Maps, often contributing a majority of the feature work. In our day-to-day engineering work, we Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.