adium / Source / AIWindowDraggingView.m

//
//  AIWindowDraggingView.m
//  Adium
//
//  Created by Evan Schoenberg on 3/6/06.
//

#import "AIWindowDraggingView.h"

/*!
 * @class AIWindowDraggingView
 * @brief This NSView subclass makes the window move when it is dragged by the view itself (but not by subviews).
 *
 * The code is, for reference, a stripped down version of the code powering AIBorderlessWindow's dragging movements.
 *
 * On mouse down, the window's frame is noted; deltas as the mouse moves are used to determine the window's
 * own movements.
 */
@implementation AIWindowDraggingView
/*!
 * @brief Mouse dragged
 */
- (void)mouseDragged:(NSEvent *)theEvent
{
        NSWindow        *window = [self window];
        NSPoint         currentLocation, newOrigin;
        NSRect          newWindowFrame;
        
        /* If we get here and aren't yet in a left mouse event, which can happen if the user began dragging while
         * a contextual menu is showing, start off from the right position by getting our originalMouseLocation.
         */             
        if (!inLeftMouseEvent) {
                //Grab the mouse location in global coordinates
                originalMouseLocation = [window convertBaseToScreen:[theEvent locationInWindow]];
                windowFrame = [window frame];
                inLeftMouseEvent = YES;         
        }
        
        newOrigin = windowFrame.origin;
        newWindowFrame = windowFrame;
        
        //Grab the current mouse location to compare with the location of the mouse when the drag started (stored in mouseDown:)
        currentLocation = [NSEvent mouseLocation];
        newOrigin.x += (currentLocation.x - originalMouseLocation.x);
        newOrigin.y += currentLocation.y - originalMouseLocation.y;
        
        newWindowFrame.origin = newOrigin;
        
        [[NSNotificationCenter defaultCenter] postNotificationName:NSWindowWillMoveNotification object:window];
        [window setFrameOrigin:newWindowFrame.origin];
        [[NSNotificationCenter defaultCenter] postNotificationName:NSWindowDidMoveNotification object:window];          
}

/*!
 * @brief Mouse down
 *
 * We start tracking the a drag operation here when the user first clicks the mouse without command presed
 * to establish the initial location.
 */
- (void)mouseDown:(NSEvent *)theEvent
{
        NSWindow        *window = [self window];
        
        //grab the mouse location in global coordinates
        originalMouseLocation = [window convertBaseToScreen:[theEvent locationInWindow]];
        windowFrame = [window frame];
        inLeftMouseEvent = YES;
}

/*!
 * @brief Mouse up
 */
- (void)mouseUp:(NSEvent *)theEvent
{
        inLeftMouseEvent = NO;
}

@end