IG_dspl_scroll

This function is designed to handle scrollbar messages from an hWnd window.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_dspl_scroll_handle( [IN] HIGEAR hIGear, [IN] DWORD dwGrpID, [IN] HWND hWnd, [IN] AT_MODE nScrlType, [IN] AT_MODE nScrlMode, [IN] LONG lScrlValue, [OUT] LPAT_SCROLL_INFO lpScrollInfo );

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AT_ERRCOUNT   ACCUAPI  IG_dspl_scroll_handle( 
        [IN] HIGEAR hIGear, 
        [IN] DWORD dwGrpID,
        [IN] HWND hWnd, 
        [IN] AT_MODE nScrlType,
        [IN] AT_MODE nScrlMode,
        [IN] LONG lScrlValue,
        [OUT] LPAT_SCROLL_INFO lpScrollInfo
);

Arguments:

Name	Type	Description
hIGear	HIGEAR	ImageGear handle of image.
dwGrpID	DWORD	Identifier of group that will be used to perform operation.
hWnd	HWND	Pointer to NSView or NSScrollView object where image is displayed and where scrolling is performed. Pointer must be casted to non-retainable HWND type type with (__bridge HWND) operator.
nScrlType	AT_MODE	Scroll command. Its value is platform dependent. For Mac platforms, valid values are: IG_DSPL_SCROLL_HORIZONTAL IG_DSPL_SCROLL_VERTICAL IG_DSPL_SCROLL_HORIZONTAL \| IG_DSPL_SCROLL_VERTICAL
nScrlMode	AT_MODE	Scroll command. Its value is platform dependent. For Mac platforms it should be 0.
nScrlValue	LONG	Scroll value. It is also platform dependent and its value may have a different meaning from nScrlType. Under the Mac platform, it is not used because the scroll position is obtained directly from the scrollbars.
lpScrollInfo	LPAT_SCROLL_INFO	Receive updated scroll parameters (not scrollbar). If NULL then it is ignored.

Return Value:

Returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear Professional.

Example:

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// MainScrollView.h #import <Cocoa/Cocoa.h> @interface MainScrollView : NSScrollView @end // MainScrollView.m #import "MainScrollView.h" #import <ImageGear18/gear.h> … // Register scrolling notification - (void)awakeFromNib { [[self contentView] setPostsBoundsChangedNotifications: YES]; NSNotificationCenter center = [NSNotificationCenter defaultCenter] ; [center addObserver: self selector: @selector(boundsDidChangeNotification:) name: NSViewBoundsDidChangeNotification object: [self contentView]]; } // Handle scrolling notification - (void) boundsDidChangeNotification: (NSNotification ) notification { IG_dspl_scroll_handle(hIGear, 0, (__bridge HWND)self, IG_DSPL_SCROLL_HORIZONTAL \| IG_DSPL_SCROLL_VERTICAL, 0, 0, NULL); [self setNeedsDisplay: YES]; }

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//  MainScrollView.h
#import <Cocoa/Cocoa.h>

@interface MainScrollView : NSScrollView
@end

//  MainScrollView.m
#import "MainScrollView.h"
#import <ImageGear18/gear.h>
…
//  Register scrolling notification
- (void)awakeFromNib
{
    [[self contentView] setPostsBoundsChangedNotifications: YES];
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter] ;
    [center addObserver: self
               selector: @selector(boundsDidChangeNotification:)
                   name: NSViewBoundsDidChangeNotification
                 object: [self contentView]];
}
//  Handle scrolling notification
- (void) boundsDidChangeNotification: (NSNotification *) notification
{
    IG_dspl_scroll_handle(hIGear, 0, (__bridge HWND)self, IG_DSPL_SCROLL_HORIZONTAL | IG_DSPL_SCROLL_VERTICAL, 0, 0, NULL);
    [self setNeedsDisplay: YES];
 }

Remarks:

This function should not be used to set the absolute scroll position; function IG_dspl_scroll_to() should be used instead.