macOS mouseMoved question

[robvas]

Pretend you have a chess/checkerboard type setup, and you want to highlight the square on the board that is under the mouse cursor. I have it working except that you have to click the mouse in order for it to work.

I would like it to automatically highlight once you roll the mouse cursor over it, but it's not working. I have tried to send the setacceptsMouseMoved:YES message, but I guess I'm not doing it wrong.

Can someone point me in the right direction? Here's the code:

//
//  StretchView.m
//

#import "StretchView.h"

@implementation StretchView

/*** this doesn't seem to affect anything 
 
- (void)awakeFromNib
{
	[[self window] setAcceptsMouseMovedEvents:YES];
}
 
***/
 
/*** this doesn't either
 
- (id)initWithFrame:(NSRect)frame
{
	self = [super initWithFrame:frame];
	
	if (self)
	{
		if ([self window] != nil)
			[[self window] setAcceptsMouseMovedEvents:YES];
	}
	return self;
}
***/

- (void)drawRect:(NSRect)rect
{
	NSBezierPath *highlightRect = [NSBezierPath bezierPath];
	NSRect bounds = [self bounds];
	
	[[NSColor grayColor] set];
	[NSBezierPath fillRect:bounds];
	
	NSPoint highlight[] = { tx*16, ty*16, 
							tx*16, (ty*16)+16,
							(tx*16)+16, (ty*16)+16,
							(tx*16)+16, ty*16 };

	[highlightRect moveToPoint:highlight[0]];
	[highlightRect lineToPoint:highlight[1]];
	[highlightRect lineToPoint:highlight[2]];
	[highlightRect lineToPoint:highlight[3]];
	[highlightRect closePath];
	
	[[NSColor yellowColor] set];
	[highlightRect stroke];
}


- (void)mouseMoved:(NSEvent *)event
{
	NSPoint p = [event locationInWindow];
	downPoint = [self convertPoint:p fromView:nil];
	currentPoint = downPoint;
	
	[self setNeedsDisplay:YES];
	
	hx = downPoint.x;
	hy = downPoint.y;
	
	NSLog(@"Real X: %f, Real Y: %f. Chosen tile = (%f, %f)", 
		  downPoint.x, downPoint.y, tx, ty);
}


- (void)mouseDown:(NSEvent *)event
{
	NSPoint p = [event locationInWindow];
	downPoint = [self convertPoint:p fromView:nil];
	currentPoint = downPoint;
	
	[self setNeedsDisplay:YES];
	
	hx = downPoint.x;
	hy = downPoint.y;
	
	tx = floor(hx / 16);
	ty = floor(hy / 16);
	
	NSLog(@"Real X: %f, Real Y: %f. Chosen tile = (%f, %f)", 
		  hx, hy, tx, ty);
}

@end

//
//  StretchView.h
//
//

#import <Cocoa/Cocoa.h>

@interface StretchView : NSView {
	
	NSPoint downPoint, currentPoint;
	
	float tx, ty;
	float hx, hy;
 
}

@end

StretchView is just a subclass of NSView, embedded in an NSScroller

 

[Peter Maurer]

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