/*

     File: AboutPanelController.m 

 Abstract: Controller for the about window. 

  Version: 1.2 

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 be used to endorse or promote products derived from the Apple Software 

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 expressly stated in this notice, no other rights or licenses, express or 

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 The Apple Software is provided by Apple on an "AS IS" basis.  APPLE 

 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION 

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 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS. 

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 */

#import "AboutPanelController.h"

//  Another approach would be to allow changing these through NSUserDefaults

#define SCROLL_DELAY_SECONDS    0.03    // time between animation frames

#define SCROLL_AMOUNT_PIXELS    1.00    // amount to scroll in each animation frame

//  We pad this many blank lines at the end of the text, so the visible part

//  of the text can scroll out of sight.

#define BLANK_LINE_COUNT        50

@implementation AboutPanelController

#pragma mark PRIVATE INSTANCE METHODS

- (void) createPanelToDisplay

{

    //  Programmatically create the new panel

    panelToDisplay = [[NSFancyPanel alloc]

        initWithContentRect: [[panelInNib contentView] frame]

        styleMask: NSBorderlessWindowMask

        backing: [panelInNib backingType]

        defer: NO];

    // Make us the controller

    [(NSFancyPanel *)panelToDisplay setController:self];

    //  Tweak esthetics, making it all white and with a shadow

    [panelToDisplay setBackgroundColor:[NSColor whiteColor]];

    [panelToDisplay setHasShadow:YES];

    [panelToDisplay setBecomesKeyOnlyIfNeeded:NO];

    //  We want to know if the window is no longer key/main

    [panelToDisplay setDelegate:self];

    //  Move the guts of the nib-based panel to the programmatically-created one

    {

        NSView *content;

        content = [[panelInNib contentView] retain];

        [content removeFromSuperview];

        [panelToDisplay setContentView: content];

        [content release];

    }

}

// Take version information from standard keys in the applicationÕs bundle

// dictionary and display it.

//

- (void) displayVersionInfo

{

    NSString *value;

    value = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];

    if (value != nil)

    {

        [shortInfoField setStringValue: value];

    }

    value = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"];

    if (value != nil)

    {

        value = [@"Version " stringByAppendingString:value];

        [versionField setStringValue: value];

    }

}

//  Watch for notifications that the application is no longer active, or that

//  another window has replaced the About panel as the main window, and hide

//  on either of these notifications.

//

- (void)watchForNotificationsWhichShouldHidePanel

{

    // This works better than just making the panel hide when the app

    // deactivates (setHidesOnDeactivate:YES), because if we use that

    // then the panel will return when the app reactivates.

    //

    [[NSNotificationCenter defaultCenter] addObserver:self

        selector:@selector(hidePanel)

        name:NSApplicationWillResignActiveNotification

        object:nil];

    // If the panel is no longer main, hide it.

    // (We could also use the delegate notification for this.)

    //

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(hidePanel)

                                                 name:NSWindowDidResignMainNotification

                                               object:panelToDisplay];

}

// Get and return the text to scroll. This implementation just loads the contents

// of the ÒREADME.rtfÓ in the main bundle. You might choose a different file, or

// a completely different implementation.

//

- (NSAttributedString *) textToScroll

{

    NSString *path;

    // Locate the README.rtf inside the applicationÕs bundle.

    path = [[NSBundle mainBundle] pathForResource: @"AboutContent" ofType: @"rtf"];

    // Suck the contents of the rich text file into a mutable Òattributed stringÓ.

    return [[[NSMutableAttributedString alloc] initWithPath:path documentAttributes:NULL] autorelease];

}

// Load the text to scroll into the scrolling text view. The odd thing here is

// that we load not only the text you'd expect, but also a bunch of blank lines

// at the end. The blank lines allow the real text to scroll out of sight.

//

- (void)loadTextToScroll

{

    NSMutableAttributedString *textToScroll;

    NSAttributedString *newline;

    //  Get whatever text we want to display

    textToScroll = [[self textToScroll] mutableCopy];

    // Append a bunch of blank lines to the end of the text, so it can always

    // scroll out of sight. This is not an elegant solution, and could fail if

    // the window and view are sufficiently tall. (I choose not to listen to

    // the rumors of the 5-meter tall Apple Drive-In Display.)

    // Make up one newline

    newline = [[[NSAttributedString alloc] initWithString: @"\n"] autorelease];

    // Append that one newline to the real text a bunch of times

    for (NSInteger i = 0; i < BLANK_LINE_COUNT; i++)

        [textToScroll appendAttributedString:newline];

    // Put the final result into the UI

    [[textView textStorage] setAttributedString:textToScroll];

}

//  Scroll to hide the top 'newAmount' pixels of the text

- (void)setScrollAmount:(float)newAmount

{

    // Scroll so that (0, amount) is at the upper left corner of the scroll view

    // (in other words, so that the top 'newAmount' scan lines of the text

    // is hidden).

    //

    [[textScrollView documentView] scrollPoint:NSMakePoint(0.0, newAmount)];

    // If anything overlaps the text we just scrolled, it wonÕt get redraw by the

    // scrolling, so force everything in that part of the panel to redraw.

    {

        NSRect scrollViewFrame;

        // Find where the scrollviewÕs bounds are, then convert to panelÕs coordinates

        scrollViewFrame = [textScrollView bounds];

        scrollViewFrame = [[panelToDisplay contentView] convertRect:scrollViewFrame fromView:textScrollView];

        // Redraw everything which overlaps it.

        [[panelToDisplay contentView] setNeedsDisplayInRect: scrollViewFrame];

    }

}

// Scroll one frame of animation

- (void)scrollOneUnit

{

    float currentScrollAmount;

    // How far have we scrolled so far?

    currentScrollAmount = [textScrollView documentVisibleRect].origin.y;

    // Scroll one unit more

    [self setScrollAmount:(currentScrollAmount + SCROLL_AMOUNT_PIXELS)];

}

// If we don't already have a timer, start one messaging us regularly

- (void)startScrollingAnimation

{

    // Already scrolling?

    if (scrollingTimer != nil)

        return;

    // Start a timer which will send us a 'scrollOneUnit' message regularly

    scrollingTimer = [[NSTimer scheduledTimerWithTimeInterval:SCROLL_DELAY_SECONDS

                                                       target:self

                                                     selector:@selector(scrollOneUnit)

                                                     userInfo:nil

                                                      repeats:YES] retain];

}

// Stop the timer and forget about it

- (void)stopScrollingAnimation

{

    [scrollingTimer invalidate];

    [scrollingTimer release];

    scrollingTimer = nil;

}

#pragma mark PUBLIC CLASS METHODS

+ (AboutPanelController *)sharedInstance

{

    static AboutPanelController *sharedInstance = nil;

    if (sharedInstance == nil)

    {

        sharedInstance = [[self alloc] init];

        [NSBundle loadNibNamed:@"AboutPanel.nib" owner:sharedInstance];

    }

    return sharedInstance;

}

#pragma mark PUBLIC INSTANCE METHODS

// Show the panel, starting the text at the top with the animation going

- (void)showPanel

{

    // Scroll to the top

    [self setScrollAmount: 0.0];

    [self startScrollingAnimation];

    // Make it the key window so it can watch for keystrokes

    [panelToDisplay makeKeyAndOrderFront:nil];

}

// Stop scrolling and hide the panel. (We stop the scrolling only to avoid

// wasting the processor, since if we kept scrolling it wouldnÕt be visible anyway.)

//

- (void)hidePanel

{

    [self stopScrollingAnimation];

    [panelToDisplay orderOut: nil];

}

//  This method exists only because this is a developer example.

//  You wouldnÕt want it in a real application.

//

- (void)setShowsScroller:(BOOL)newSetting

{

    [textScrollView setHasVerticalScroller:newSetting];

}

#pragma mark PUBLIC INSTANCE METHODS -- NSNibAwaking INFORMAL PROTOCOL

- (void)awakeFromNib

{

    //  Create 'panelToDisplay', a borderless window, using the guts of the more vanilla 'panelInNib'.

    [self createPanelToDisplay];

    //  Fill in text fields

    [self displayVersionInfo];

    [self loadTextToScroll];

    //  Make things look nice

    [panelToDisplay center];

    //  Make lots of other things dismiss the panel

    [self watchForNotificationsWhichShouldHidePanel];

}

#pragma mark PUBLIC INSTANCE METHODS -- NSFancyPanel DELEGATE

- (BOOL)handlesKeyDown: (NSEvent *)keyDown inWindow:(NSWindow *)window

{

    // Close the panel on any keystroke.

    // We could also check for the Escape key by testing

    //      [[keyDown characters] isEqualToString: @"\033"]

    [self hidePanel];

    return YES;

}

- (BOOL)handlesMouseDown:(NSEvent *)mouseDown inWindow:(NSWindow *)window

{

    // Close the panel on any click

    [self hidePanel];

    return YES;

}

@end