ScalingScrollView.m

/*
     File: ScalingScrollView.m
 Abstract: A subclass of NSScrollView that supports content scaling.
  Version: 1.7.1
 
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 */

#import <Cocoa/Cocoa.h>
#import "ScalingScrollView.h"

/* For genstrings:
    NSLocalizedStringFromTable(@"10%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"25%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"50%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"75%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"100%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"125%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"150%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"200%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"400%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"800%", @"ZoomValues", @"Zoom popup entry")
    NSLocalizedStringFromTable(@"1600%", @"ZoomValues", @"Zoom popup entry")
*/   
static NSString *_NSDefaultScaleMenuLabels[] = {/* @"Set...", */ @"10%", @"25%", @"50%", @"75%", @"100%", @"125%", @"150%", @"200%", @"400%", @"800%", @"1600%"};
static const CGFloat _NSDefaultScaleMenuFactors[] = {/* 0.0, */ 0.1, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 4.0, 8.0, 16.0};
static NSUInteger _NSDefaultScaleMenuSelectedItemIndex = 4;
static const CGFloat _NSScaleMenuFontSize = 10.0;

@implementation ScalingScrollView

- (id)initWithFrame:(NSRect)rect {
    if ((self = [super initWithFrame:rect])) {
        scaleFactor = 1.0;
    }
    return self;
}

- (void)makeScalePopUpButton {
    if (_scalePopUpButton == nil) {
        NSUInteger cnt, numberOfDefaultItems = (sizeof(_NSDefaultScaleMenuLabels) / sizeof(NSString *));
        id curItem;

        // create it
        _scalePopUpButton = [[NSPopUpButton allocWithZone:[self zone]] initWithFrame:NSMakeRect(0.0, 0.0, 1.0, 1.0) pullsDown:NO];
        [(NSPopUpButtonCell *)[_scalePopUpButton cell] setBezelStyle:NSShadowlessSquareBezelStyle];
        [[_scalePopUpButton cell] setArrowPosition:NSPopUpArrowAtBottom];
        
        // fill it
        for (cnt = 0; cnt < numberOfDefaultItems; cnt++) {
            [_scalePopUpButton addItemWithTitle:NSLocalizedStringFromTable(_NSDefaultScaleMenuLabels[cnt], @"ZoomValues", nil)];
            curItem = [_scalePopUpButton itemAtIndex:cnt];
            if (_NSDefaultScaleMenuFactors[cnt] != 0.0) {
                [curItem setRepresentedObject:[NSNumber numberWithDouble:_NSDefaultScaleMenuFactors[cnt]]];
            }
        }
        [_scalePopUpButton selectItemAtIndex:_NSDefaultScaleMenuSelectedItemIndex];

        // hook it up
        [_scalePopUpButton setTarget:self];
        [_scalePopUpButton setAction:@selector(scalePopUpAction:)];

        // set a suitable font
        [_scalePopUpButton setFont:[NSFont toolTipsFontOfSize:_NSScaleMenuFontSize]];

        // Make sure the popup is big enough to fit the cells.
        [_scalePopUpButton sizeToFit];

	// don't let it become first responder
	[_scalePopUpButton setRefusesFirstResponder:YES];

        // put it in the scrollview
        [self addSubview:_scalePopUpButton];
        [_scalePopUpButton release];
    }
}

- (void)tile {
    // Let the superclass do most of the work.
    [super tile];

    if (![self hasHorizontalScroller]) {
        if (_scalePopUpButton) [_scalePopUpButton removeFromSuperview];
        _scalePopUpButton = nil;
    } else {
	NSScroller *horizScroller;
	NSRect horizScrollerFrame, buttonFrame = NSZeroRect;
        id documentView = [self documentView];
	BOOL showsPopup = (([documentView respondsToSelector:@selector(showsScalePopUpButton)] && [documentView showsScalePopUpButton]) ? YES : NO);

        if (showsPopup) {
            if (!_scalePopUpButton) [self makeScalePopUpButton];
            buttonFrame = [_scalePopUpButton frame];
        } else {
            [_scalePopUpButton removeFromSuperview];
            _scalePopUpButton = nil;
        }

        horizScroller = [self horizontalScroller];
        horizScrollerFrame = [horizScroller frame];

        // Now we'll just adjust the horizontal scroller size and set the button size and location.
        horizScrollerFrame.size.width = horizScrollerFrame.size.width - buttonFrame.size.width;
        [horizScroller setFrameSize:horizScrollerFrame.size];

        if (showsPopup) {
            buttonFrame.origin.x = NSMaxX(horizScrollerFrame);
            buttonFrame.size.height = horizScrollerFrame.size.height + 1.0;
            buttonFrame.origin.y = [self bounds].size.height - buttonFrame.size.height + 1.0;
            [_scalePopUpButton setFrame:buttonFrame];
        }            
    }
}

- (void)drawRect:(NSRect)rect {
    NSRect verticalLineRect;
    
    [super drawRect:rect];

    if ([_scalePopUpButton superview]) {
        verticalLineRect = [_scalePopUpButton frame];
        verticalLineRect.origin.x -= 1.0;
        verticalLineRect.size.width = 1.0;
        if (NSIntersectsRect(rect, verticalLineRect)) {
            [[NSColor blackColor] set];
            NSRectFill(verticalLineRect);
        }
    }
}

- (IBAction)scalePopUpAction:(id)sender {
    NSNumber *selectedFactorObject = [[sender selectedCell] representedObject];
    
    if (selectedFactorObject == nil) {
        NSLog(@"Scale popup action: setting arbitrary zoom factors is not yet supported.");
        return;
    } else {
        [self setScaleFactor:[selectedFactorObject doubleValue] adjustPopup:NO];
    }
}

- (CGFloat)scaleFactor {
    return scaleFactor;
}

- (void)setScaleFactor:(CGFloat)newScaleFactor {
    if (scaleFactor != newScaleFactor) {
	scaleFactor = newScaleFactor;

	NSView *clipView = [[self documentView] superview];
	
	// Get the frame.  The frame must stay the same.
	NSSize curDocFrameSize = [clipView frame].size;
	
	// The new bounds will be frame divided by scale factor
	NSSize newDocBoundsSize = {curDocFrameSize.width / scaleFactor, curDocFrameSize.height / scaleFactor};
	
	[clipView setBoundsSize:newDocBoundsSize];
    }
}

- (void)setScaleFactor:(CGFloat)newScaleFactor adjustPopup:(BOOL)flag {
    if (flag) {	// Coming from elsewhere, first validate it
	NSUInteger cnt = 0, numberOfDefaultItems = (sizeof(_NSDefaultScaleMenuFactors) / sizeof(CGFloat));

	// We only work with some preset zoom values, so choose one of the appropriate values (Fudge a little for floating point == to work)
	while (cnt < numberOfDefaultItems && newScaleFactor * .99 > _NSDefaultScaleMenuFactors[cnt]) cnt++;
	if (cnt == numberOfDefaultItems) cnt--;
	[_scalePopUpButton selectItemAtIndex:cnt];
	newScaleFactor = _NSDefaultScaleMenuFactors[cnt];
    }
    [self setScaleFactor:newScaleFactor];
}

- (void)setHasHorizontalScroller:(BOOL)flag {
    if (!flag) [self setScaleFactor:1.0 adjustPopup:NO];
    [super setHasHorizontalScroller:flag];
}

/* Reassure AppKit that ScalingScrollView supports live resize content preservation, even though it's a subclass that could have modified NSScrollView in such a way as to make NSScrollView's live resize content preservation support inoperative. By default this is disabled for NSScrollView subclasses.
*/
- (BOOL)preservesContentDuringLiveResize {
    return [self drawsBackground];
}


@end