NSView Subclass

[MacRumors Guy]

I have question about NSView:

Imagine a Custom View where the mouseDown, mouseDrag and mouseUp methods are overriden so the user can drag a point (NSRect) on the screen. To drag it I need the mouse coordinates relative to the current view. This is not a problem when the parent of the view is the window, but how do I get them when the view is inside another view?



@implementation MyView

- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
pointXPosition = 200.0f;
pointYPosition = 200.0f;

locked = NO;
}
return self;
}

- (void) drawRect:(NSRect)rect {

NSRect point = NSMakeRect(pointXPosition, pointYPosition, 6.0f, 6.0f);
[[NSColor redColor] set];
NSRectFill(point);

}

- (void)mouseDown:(NSEvent *)theEvent {
NSPoint mousePos = [theEvent locationInWindow];
NSRect frame = [super frame];
CGFloat deltaX = mousePos.x - frame.origin.x - pointXPosition;
CGFloat deltaY = mousePos.y - frame.origin.y - pointYPosition;
if(sqrtf(deltaX * deltaX + deltaY * deltaY) < 100.0f)
locked = YES;
}

- (void)mouseUp:(NSEvent *)theEvent {
locked = NO;
}

- (void)mouseDragged:(NSEvent *)theEvent {

if(locked) {
NSPoint mousePos = [theEvent locationInWindow];

NSRect frame = [super frame];

CGFloat oldXPos = pointXPosition;
CGFloat oldYPos = pointYPosition;

pointXPosition = mousePos.x - frame.origin.x;
pointYPosition = mousePos.y - frame.origin.y;

CGFloat rectToDisplayXMin = MIN(oldXPos, pointXPosition);
CGFloat rectToDisplayYMin = MIN(oldYPos, pointYPosition);

CGFloat rectWidthToDisplay = MAX(oldXPos, pointXPosition) - rectToDisplayXMin;
CGFloat rectHeigthToDisplay = MAX(oldYPos, pointYPosition) - rectToDisplayYMin;

NSRect dirtyRect = NSMakeRect(rectToDisplayXMin,
rectToDisplayYMin,
rectWidthToDisplay + 6.0f,
rectHeigthToDisplay + 6.0f);

[self setNeedsDisplayInRect:dirtyRect];
}
}

[kainjow]

Do this: NSPoint mousePos = [self convertPoint:[theEvent locationInWindow] fromView:nil]; By passing nil, you're converting the coordinates from the window to the view (self).

[MacRumors Guy]

Thanks!!!