levelview.m

在iPhone OS上使用用Objective-C语言开发的Demo程序

/*

===== IMPORTANT =====

This is sample code demonstrating API, technology or techniques in development.
Although this sample code has been reviewed for technical accuracy, it is not
final. Apple is supplying this information to help you plan for the adoption of
the technologies and programming interfaces described herein. This information
is subject to change, and software implemented based on this sample code should
be tested with final operating system software and final documentation. Newer
versions of this sample code may be provided with future seeds of the API or
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documentation, view the New & Updated sidebars in subsequent documentation
seeds.

=====================

File: LevelView.m
Abstract: LevelView builds and displays the primary user interface of the Bubble
Level application.

Version: 1.7

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*/

#import "LevelView.h"
#import "CalibrationView.h"
#import "SoundEffect.h"
#import <QuartzCore/QuartzCore.h>

#define kMaxVariationForFarSound 6.0
#define kMaxVariationForNearSound 2.0
#define kMaxVariationForLevelSound 0.5
#define kMaxAngle 90.0

CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};


@interface LevelView (PrivateMethods)
- (void)setupSounds;
- (void)setupSubviewsWithContentFrame:(CGRect)frameRect;
@end


@implementation LevelView

@synthesize viewController;

#pragma mark -
#pragma mark === Setting up / Tearing down ===
#pragma mark -

- (id)initWithFrame:(CGRect)frame viewController:(LevelViewController *)aController {
    self = [super initWithFrame:frame];
    if (self != nil) {
        self.viewController = aController;

        // set default state
        holdButtonIsShowing = YES;
        
        // set up sounds and views
        [self setupSounds];
        [self setupSubviewsWithContentFrame:frame];
    }
    return self;
}

- (void)setupSounds {
    NSBundle *mainBundle = [NSBundle mainBundle];

    farSound = [[SoundEffect alloc] initWithContentsOfFile:[mainBundle pathForResource:@"farSound" ofType:@"caf"]];
    nearSound = [[SoundEffect alloc] initWithContentsOfFile:[mainBundle pathForResource:@"nearSound" ofType:@"caf"]];
    levelSound = [[SoundEffect alloc] initWithContentsOfFile:[mainBundle pathForResource:@"levelSound" ofType:@"caf"]];
}

- (UIButton *)buttonWithTitle:(NSString *)title target:(id)target selector:(SEL)inSelector frame:(CGRect)frame image:(UIImage*)image {
	UIButton *button = [[UIButton alloc] initWithFrame:frame];
	button.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
	button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
	[button setTitle:title forState:UIControlStateNormal & UIControlStateHighlighted & UIControlStateSelected];
	[button setTitleColor:[UIColor blackColor] forState:UIControlEventTouchDown];
	UIImage *newImage = [image stretchableImageWithLeftCapWidth:10 topCapHeight:10];
	[button setBackgroundImage:newImage forState:UIControlStateNormal];
	[button addTarget:target action:inSelector forControlEvents:UIControlEventTouchUpInside];
    button.adjustsImageWhenDisabled = YES;
    button.adjustsImageWhenHighlighted = YES;
	[button setBackgroundColor:[UIColor clearColor]];	// in case the parent view draws with a custom color or gradient, use a transparent color
    [button autorelease];
    return button;
}

- (void)setupSubviewsWithContentFrame:(CGRect)frameRect {    
    UIImageView *levelFrontView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"levelBackground.png"]];
    levelFrontView.center = self.center;
    levelFrontView.opaque = YES;
   
    // set up bubble view
    bubbleView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bubble.png"]];
    bubbleView.center = self.center;
    
    // set up vial lines view
    UIImageView *vialLinesView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"vial_lines.png"]];
    vialLinesView.center = self.center;
    
    // set up up/down arrow view
    upDownArrowsView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"arrows_cw.png"]];
    upDownArrowsView.center = self.center;

    // set up down/up arrow view
    downUpArrowsView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"arrows_ccw.png"]];
    downUpArrowsView.center = self.center;
    downUpArrowsView.hidden = YES;  

    // set up info button
    // since the 'i' image is small, we make the button frame larger than the image, and inset the image in the frame
    float infoShiftRight = 290.0;
    float infoShiftDown = 2.0;
    float insetFromEdge = 10.0;
    
	UIImage *buttonImage = [UIImage imageNamed:@"info_button.png"];
    CGRect buttonFrame = CGRectMake(infoShiftRight, infoShiftDown, buttonImage.size.width + (2 * insetFromEdge), buttonImage.size.height + (2 * insetFromEdge));
	UIButton *infoButton = [[UIButton alloc] initWithFrame:buttonFrame];
    infoButton.contentEdgeInsets = UIEdgeInsetsMake(insetFromEdge, insetFromEdge, insetFromEdge, insetFromEdge);
	infoButton.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
	infoButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
	[infoButton setImage:buttonImage forState:UIControlStateNormal];
	[infoButton addTarget:self.viewController action:@selector(flipAction:) forControlEvents:UIControlEventTouchUpInside];
    infoButton.adjustsImageWhenHighlighted = YES;

    // set up Hold button
    float holdShiftRight = 190.0;
    float holdShiftDown = 32.0;
    
	buttonImage = [UIImage imageNamed:@"hold_button.png"];
	buttonFrame = CGRectMake(holdShiftRight, holdShiftDown, buttonImage.size.width, buttonImage.size.height);
	holdButton = [self buttonWithTitle:nil target:self selector:@selector(toggleHoldButton:) frame:buttonFrame image:buttonImage];
    
    // set up shadow degree display, to give displayed text more punch
    // this is an identical text display, but in white and offset 2 pixels
    float displayTextWidth = 180.0;
    float displayTextHeight = 60.0;
    float displayShiftRight = 124.0;
    float displayShiftDown = 264.0;
    UIFont *displayFont = [UIFont fontWithName:@"Helvetica" size:60];
    shadowDegreeDisplay = [[UILabel alloc] initWithFrame:CGRectMake(displayShiftRight-2.0, displayShiftDown, displayTextWidth, displayTextHeight)];
    shadowDegreeDisplay.font = displayFont;
    shadowDegreeDisplay.textColor = [UIColor whiteColor];
    shadowDegreeDisplay.backgroundColor = [UIColor clearColor];
    shadowDegreeDisplay.textAlignment = UITextAlignmentCenter;
    
    // set up degree display
    degreeDisplay = [[UILabel alloc] initWithFrame:CGRectMake(displayShiftRight, displayShiftDown, displayTextWidth, displayTextHeight)];
    degreeDisplay.font = displayFont;
    degreeDisplay.textColor = [UIColor colorWithRed:66.0/255.0 green:73.0/255.0 blue:113.0/255.0 alpha:1.0];
    degreeDisplay.backgroundColor = [UIColor clearColor];
    degreeDisplay.textAlignment = UITextAlignmentCenter;
    
    // Transform for rotating textual display
	CATransform3D landscapeTransform = CATransform3DIdentity;
    landscapeTransform = CATransform3DRotate(landscapeTransform, DegreesToRadians(-90), 0, 0, 1);
    degreeDisplay.layer.transform = landscapeTransform;
    shadowDegreeDisplay.layer.transform = landscapeTransform;
            
    // add view in proper order and location
    [self addSubview:levelFrontView];
    [self addSubview:upDownArrowsView];
    [self addSubview:downUpArrowsView];
    [self addSubview:bubbleView];
    [self addSubview:vialLinesView];
    [self addSubview:shadowDegreeDisplay];
    [self addSubview:degreeDisplay];
    [self addSubview:holdButton];
    [self addSubview:infoButton];

    // release views we no longer need to address
    [levelFrontView release];
    [vialLinesView release];
    [infoButton release];
    
    [self setNeedsDisplay];
}

- (void)dealloc {
    [bubbleView release];
    [upDownArrowsView release];
    [downUpArrowsView release];
    [shadowDegreeDisplay release];
    [degreeDisplay release];
    [holdButton release];
    [farSound release];
    [nearSound release];
    [levelSound release];    
    [super dealloc];
}

#pragma mark -
#pragma mark === Actions ===
#pragma mark -
- (void)updateLevelSoundForAngle:(float)angle {
    float absAngle = fabs(angle);
    
    if (absAngle <= kMaxVariationForLevelSound) {
        [levelSound play];
    } else if (absAngle <= kMaxVariationForNearSound) {
        [nearSound play];
    } else if (absAngle <= kMaxVariationForFarSound) {
        [farSound play];
    }
}

- (void)updateArrowsForAngle:(float)angle {
    if (angle < 0.0) {
        downUpArrowsView.hidden = YES;
        upDownArrowsView.hidden = NO;
    } else if (angle > 0.0) {
        downUpArrowsView.hidden = NO;
        upDownArrowsView.hidden = YES;
    } else {  // turn off the arrows if we're level
        downUpArrowsView.hidden = YES;
        upDownArrowsView.hidden = YES;
    }
}

- (void)updateBubbleForAngle:(float)angle {
    float halfVialLength = 320.0 / 2;    
    float zoomAngle = angle * 4 ;  // real bubble floats up more rapidly than sine function
    
    if (zoomAngle > kMaxAngle) zoomAngle = kMaxAngle ;   // stop at the end
	if (zoomAngle < -kMaxAngle) zoomAngle = -kMaxAngle ; // stop at the other end
    
    float newY = self.center.y - sin(DegreesToRadians(zoomAngle)) * halfVialLength;
    
    bubbleView.center=CGPointMake(self.center.x, newY);
}

- (void)updateReadoutForAngle:(float)angle {
    // limit it to no more or less than the maximum angle from level
    if (angle > kMaxAngle) angle = kMaxAngle;
    if (angle < -kMaxAngle) angle = -kMaxAngle;
    
    NSString *newAngleString = [NSString stringWithFormat:@"%0.1f", angle];
    NSString *angleStringWithDegree = [newAngleString stringByAppendingString:@"º"];
    shadowDegreeDisplay.text = angleStringWithDegree;
    degreeDisplay.text = angleStringWithDegree;
    [degreeDisplay setNeedsDisplay];
    [shadowDegreeDisplay setNeedsDisplay];
}

- (void)updateToInclinationInRadians:(float)rads {
    float rotation = -RadiansToDegrees(rads);
    static int soundUpdateCounter = 0;
    
    if (holdButtonIsShowing) {  // Don't update if user has toggled the Hold button to the Release state
        [self updateReadoutForAngle:rotation];
        [self updateBubbleForAngle:rotation];
        [self updateArrowsForAngle:rotation];
        soundUpdateCounter++;
    
        if (soundUpdateCounter == 10) { // update sound at a tenth the rate of the animation
            [self updateLevelSoundForAngle:rotation];
            soundUpdateCounter = 0;
        }
    }
}

// Display only updates if Hold/Release button hasn't been pressed 
- (void)toggleHoldButton:(id)sender {
    if (holdButtonIsShowing == YES) {
        holdButtonIsShowing = NO;
        [holdButton setImage:[UIImage imageNamed:@"release_button.png"] forState:UIControlStateNormal];
    } else {
        holdButtonIsShowing = YES;
        // set image on Hold button
        [holdButton setImage:[UIImage imageNamed:@"hold_button.png"] forState:UIControlStateNormal];
    }    
}

@end