UI implementation query in IOS - iphone

I am working in an application in that I need to record and play audio file. I have done everything related to recording and playing. This time I am little confused about UI related, May be first time this confusion..
As per the above Image I need to show the playback track, so far I have done lot with progress bar and slider to show playback seconds or server response. I am checking my self to implemente this but I am not getting any exact idea to do. Can some suggest me any idea to implement the same. Your suggestions more useful for my work. Thanks in advance.

You could use the class I posted below and use it inbetween the background image and top it with the pause/play button. For the asset(little ring) at the current position you may want to use basic trigonometry.
A simple UIView subclass that draws a ring depending on a progress. It's may need some love by means of configuration of the circle radius and such:
CircleProgressView.h
#interface CircleProgressView : UIView
{
double progress_;
UIColor *color_;
}
- (void)setProgress:(float)progress;
- (void)setColor:(UIColor *)color;
#end
CircleProgressView.m
#implementation CircleProgressView
- (void)setProgress:(float)progress
{
_progress_ = progress;
[self setNeedsDisplay];
}
- (void)setColor:(UIColor *)color
{
color_ = color;
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 6);
CGContextSetStrokeColorWithColor(context, color_.CGColor);
CGContextAddArc(context,
self.frame.size.width / 2.0,
self.frame.size.height / 2.0,
self.frame.size.width / 2 - 4.5, 0.0, M_PI * progress_ * 2.0, NO);
CGContextStrokePath(context);
}

Related

how to get a pie progress bar

I like the small pie progress bar like it's in Xcode, when search for a string in the project (Shift-Command-F), see picture.
How can this be called on iOS? I'd love to have it for a download queue.
Thanks in advance.
There's no stock circular deterministic progress view. Here's an example drawRect: you might use to implement such a thing.
- (void)drawRect:(CGRect)rect
{
CGFloat circleRadius = (self.bounds.size.width / 2) - (self.strokeWidth * 2);
CGPoint circleCenter = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
CGRect circleRect = CGRectMake(circleCenter.x - circleRadius, circleCenter.y - circleRadius, 2 * circleRadius, 2 * circleRadius);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
// Draw stroked circle to delineate circle shape.
CGContextSetStrokeColorWithColor(context, self.fillColor.CGColor);
CGContextSetLineWidth(context, self.strokeWidth);
CGContextAddEllipseInRect(context, circleRect);
CGContextStrokePath(context);
// Draw filled wedge (clockwise from 12 o'clock) to indicate progress
self.progress = MIN(MAX(0.0, self.progress), 1.0);
CGFloat startAngle = -M_PI_2;
CGFloat endAngle = startAngle + (progress * 2 * M_PI);
CGContextSetFillColorWithColor(context, self.fillColor.CGColor);
CGContextMoveToPoint(context, circleCenter.x, circleCenter.x);
CGContextAddLineToPoint(context, CGRectGetMidX(circleRect), CGRectGetMinY(circleRect));
CGContextAddArc(context, circleCenter.x, circleCenter.y, circleRadius, startAngle, endAngle, NO);
CGContextClosePath(context);
CGContextFillPath(context);
CGContextRestoreGState(context);
}
You would need to create strokeWidth and fillColor properties to use this code directly, but it should be a start. Here's a sample project with a couple of examples.
Maybe you can use the code from MBProgressHUD there is a pie like this in some kind bigger.
I don't believe they're released a UIProgressView like this on iOS, but you can create it yourself. To put things in the right-hand side of a text view, use the rightView property (don't forget to set rightViewMode as well).
You can create a custom UIView for this (I doubt it'd be worth trying to subclass UIProgressView). I would probably hand-draw it with a drawRect rather than trying to use images or anything like that. Should be much easier to fill the correct percentage that way.
May be you can use SSPieProgressView
Try this: LSPieProgressView
It's an UIView Category, can show a pie progress overlay any UIView.
Code Example:
#import "UIView+LSPieProgress.h"
- (void)updateProgress
{
[self.button setProgress:self.progress];
}

Least CPU intensive way to Frequently & Repeately Draw Many Views

This Is a problem that I've been leaving and coming back to for a while now. I've never really nailed the problem.
What I've been trying to do use CADisplayLink to dynamically draw pie chart style progress. My code works fine when I have 1 - 4 uiviews updating simultaneously. When I add any more than that the drawing of the pies becomes very jerky.
I want to explain what I have been trying in the hope that somebody could point out the inefficiencies and suggest a better drawing method.
I create 16 uiviews and add a CAShapeLayer subview to each one. This is where I want to draw my pie slices.
I precalcuate 360 CGPaths representing 0 to 360 degrees of a circle and store them in an array to try and improve performance.
In a master View I start a displaylink,loop through all my other views, calculate how much of a full pie it should show, then find the right path and assign it to my shapelayer.
-(void)makepieslices
{
pies=[[NSMutableArray alloc]initWithCapacity:360];
float progress=0;
for(int i=0;i<=360;i++)
{
progress= (i* M_PI)/180;
CGMutablePathRef thePath = CGPathCreateMutable();
CGPathMoveToPoint(thePath, NULL, 0.f, 0.f);
CGPathAddLineToPoint(thePath, NULL, 28, 0.f);
CGPathAddArc(thePath, NULL, 0.f,0.f, 28, 0.f, progress, NO);
CGPathCloseSubpath(thePath);
_pies[i]=thePath;
}
}
- (void)updatePath:(CADisplayLink *)dLink {
for (int idx=0; idx<[spinnydelegates count]; idx++) {
id<SyncSpinUpdateDelegate> delegate = [spinnydelegates objectAtIndex:idx];
dispatch_async(dispatch_get_global_queue(0, 0), ^{
[delegate updatePath:dLink];
});
}
}
- (void)updatePath:(CADisplayLink *)dLink {
dispatch_async(dispatch_get_global_queue(0, 0), ^{
currentarc=[engineref getsyncpercentForPad:cid pad:pid];
int progress;
progress = roundf(currentarc*360);
dispatch_async(dispatch_get_main_queue(), ^{
shapeLayer_.path = _pies[progress];
});
});
}
This technique just straight out isnt working for me when trying to simultaneously update more than 4 or 5 pies at the same time. 16 screen updates at the same time sounds like it should really not be that big of a deal for the ipad to me. So this leads me to think I doing something very very fundamentally wrong.
I'd really appreciate if somebody could tell me why this technique results in jittery screen updates and also if they could suggest a different technique that I could go an investigate that will allow me to perform 16 simultaneous shapelayer updates smoothly.
EDIT Just to give you an idea of how bad performance is, when I have all 16 pies drawing the cpu goes up to 20%
*EDIT *
This is based on studevs advice but I don't see anything been drawn. segmentLayer is a CGLayerRef as a property of my pieview.
-(void)makepies
{
self.layerobjects=[NSMutableArray arrayWithCapacity:360];
CGFloat progress=0;
CGContextRef context=UIGraphicsGetCurrentContext();
for(int i =0;i<360;i++)
{
progress= (i*M_PI)/180.0f;
CGLayerRef segmentlayer=CGLayerCreateWithContext(context, CGSizeMake(30, 30), NULL);
CGContextRef layerContext=CGLayerGetContext(segmentlayer);
CGMutablePathRef thePath = CGPathCreateMutable();
CGPathMoveToPoint(thePath, NULL, 0.f, 0.f);
CGPathAddLineToPoint(thePath, NULL, 28, 0.f);
CGPathAddArc(thePath, NULL, 0.f,0.f, 28, 0.f, progress, NO);
CGPathCloseSubpath(thePath);
[layerobjects addObject:(id)segmentlayer];
CGLayerRelease(segmentlayer);
}
}
-(void)updatePath
{
int progress;
currentarc=[engineref getsyncpercent];
progress = roundf(currentarc*360);
//shapeLayer_.path = _pies[progress];
self.pieView.segmentLayer=(CGLayerRef)[layerobjects objectAtIndex:progress];
[self.pieView setNeedsDisplay];
}
-(void)drawRect:(CGRect)rect
{
CGContextRef context=UIGraphicsGetCurrentContext();
CGContextDrawLayerInRect(context, self.bounds, segmentLayer);
}
I think one of the first things you should look to do is buffer your segments (currently represented by CGPath objects) offscreen using CGLayer objects. From the docs:
Layers are suited for the following:
High-quality offscreen rendering of drawing that you plan to reuse.
For example, you might be building a scene and plan to reuse the same
background. Draw the background scene to a layer and then draw the
layer whenever you need it. One added benefit is that you don’t need
to know color space or device-dependent information to draw to a
layer.
Repeated drawing. For example, you might want to create a
pattern that consists of the same item drawn over and over. Draw the
item to a layer and then repeatedly draw the layer, as shown in Figure
12-1. Any Quartz object that you draw repeatedly—including CGPath,
CGShading, and CGPDFPage objects—benefits from improved performance if
you draw it to a CGLayer. Note that a layer is not just for onscreen
drawing; you can use it for graphics contexts that aren’t
screen-oriented, such as a PDF graphics context.
Create a UIView subclass that draws the pie. Give it an instance variable for that pie's current progress, and override drawRect: to draw the layer representing that progress. The view needs to first get a reference the required CGLayer object, so implement a delegate with the method:
- (CGLayerRef)pieView:(PieView *)pieView segmentLayerForProgress:(NSInteger)progress context:(CGContextRef)context;
It will then become the delegate's job to return an existing CGLayerRef, or if it doesn't exist yet, create it. Since the CGLayer can only be created from within drawRect:, this delegate method should be called from PieView's drawRect: method. PieView should look something like this:
PieView.h
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#class PieView;
#protocol PieViewDelegate <NSObject>
#required
- (CGLayerRef)pieView:(PieView *)pieView segmentLayerForProgress:(NSInteger)progress context:(CGContextRef)context;
#end
#interface PieView : UIView
#property(nonatomic, weak) id <PieViewDelegate> delegate;
#property(nonatomic) NSInteger progress;
#end
PieView.m
#import "PieView.h"
#implementation PieView
#synthesize delegate, progress;
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGLayerRef segmentLayer = [delegate pieView:self segmentLayerForProgress:self.progress context:context];
CGContextDrawLayerInRect(context, self.bounds, segmentLayer);
}
#end
Your PieView's delegate (most likely your view controller) then implements:
NSString *const SegmentCacheKey = #"SegmentForProgress:";
- (CGLayerRef)pieView:(PieView *)pieView segmentLayerForProgress:(NSInteger)progress context:(CGContextRef)context
{
// First, try to retrieve the layer from the cache
NSString *cacheKey = [SegmentCacheKey stringByAppendingFormat:#"%d", progress];
CGLayerRef segmentLayer = (__bridge_retained CGLayerRef)[segmentsCache objectForKey:cacheKey];
if (!segmentLayer) { // If the layer hasn't been created yet
CGFloat progressAngle = (progress * M_PI) / 180.0f;
// Create the layer
segmentLayer = CGLayerCreateWithContext(context, layerSize, NULL);
CGContextRef layerContext = CGLayerGetContext(segmentLayer);
// Draw the segment
CGContextSetFillColorWithColor(layerContext, [[UIColor blueColor] CGColor]);
CGContextMoveToPoint(layerContext, layerSize.width / 2.0f, layerSize.height / 2.0f);
CGContextAddArc(layerContext, layerSize.width / 2.0f, layerSize.height / 2.0f, layerSize.width / 2.0f, 0.0f, progressAngle, NO);
CGContextClosePath(layerContext);
CGContextFillPath(layerContext);
// Cache the layer
[segmentsCache setObject:(__bridge_transfer id)segmentLayer forKey:cacheKey];
}
return segmentLayer;
}
So for each pie, create a new PieView and set it's delegate. When you need to update a pie, update the PieView's progress property and call setNeedsDisplay.
I'm using an NSCache here since there are a lot of graphics being stored, and it could take up a lot of memory. You could also limit the number of segments being drawn - 100 is probably plenty. Also, I agree with other comments/answers that you might try updating the views less often, as this will consume less CPU and battery power (60fps is probably not necessary).
I did some crude testing of this method on an iPad (1st gen) and managed to get well over 50 pies updating at 30fps.
dubbeat: ...CADisplayLink...
Justin: do you need to draw at the display's refresh rate?
dubbeat: The progress of the pie drawing is supposed to represent the progress of an mp3s playback progress so I guess at the displays refresh rate at a minimum.
That's much faster than is necessary, unless you're trying to display some really, really, really exotic visualizer, which is very unlikely if your spinner's radius is 28pt. Also, there's no reason to draw faster than the display's frequency.
One side effect is that your spinner's superviews may also updating at this high frequency. If you can make the spinner view opaque, then you can reduce overdrawing of superviews (and subviews if you have them).
60fps is a good number for a really fast desktop game. For an ornament/progress bar, it's far more than necessary.
Try this:
not using CADisplayLink, but the standard view system
use an NSTimer on the main run loop, begin with a frequency of 8 Hz*
adjust timer to taste
then let us know if that is adequately fast.
*the timer callback calls [spinner setNeedsDisplay]
Well, you could achieve some performance improvement by pre-assembling the background view, capturing the image of it, and then just using the image in an image view for the background. You could go further by capturing a view of the "relatively static" parts of your chart, updating that static view only when necessary.
Store your 360 circle segments as textures and use OpenGL to animate the sequences.

NSArray from SQLite to draw CGRects

I'm hoping someone will be able to point me in the right direction. I'm new to iOS/Objective C, but familiar with classic ASP/PHP.
I'm trying to dynamically generate CGRects (filled ellipses) using data from an SQLite database. I am able to connect to the SQLite database and pull an array, so that's working. You'll see that I have my CGRect goal successfully writing to the NSLog, along with manually drawing two dots.
I just need a little push in the right direction as far as the best method to place items from the "record set" into the CGRect line, in a similar method to how I have it sent to the NSLog.
My working CGRect code:
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
// Set dot alpha transparency
CGContextSetAlpha(context, 0.70);
// And draw with a blue fill color
CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);
// Fill rect convenience equivalent to AddEllipseInRect(); FillPath();
int ellipseDiameter = 35.0;
int drawOffset = ellipseDiameter / 2;
//NSArray into NSLog showing how CGRect should be formatted from SQLite data
NSArray *locationInfos = [LocationDatabase database].locationInfos;
for (LocationInfo *info in locationInfos) {
NSLog(#"CGContextFillEllipseInRect(context, CGRectMake(%# - drawOffset, %# - drawOffset, ellipseDiameter,ellipseDiameter))", info.xCoordText, info.yCoordText);
}
//drawing dot 1
CGContextFillEllipseInRect(context, CGRectMake(125.0 - drawOffset, 108.0 - drawOffset, ellipseDiameter, ellipseDiameter));
//drawing dot 2
CGContextFillEllipseInRect(context, CGRectMake(132.0 - drawOffset, 146.0 - drawOffset, ellipseDiameter, ellipseDiameter));
}
Any direction would really be appreciated. Thanks in advance!
info.xCoordText and info.yCoordText are NSString, just call [info.xCoordText floatValue] to turn them into floats.
i.e.:
CGContextFillEllipseInRect(context, CGRectMake(info.xCoordText.floatValue - drawOffset, info.yCoordText.floatValue - drawOffset, ellipseDiameter,ellipseDiameter));

iphone - create animation like user location Blue marble drop

Do you know how to create an animation like the Blue Marble drop User-Location in MKMapView?
Although I am not sure on the specifics of how Apple accomplished this effect, this feels to me like a great opportunity to use CoreAnimation and custom animatable properties. This post provides some nice background on the subject. I assume by the "Blue Marble drop" animation you're referring to the following sequence:
Large light blue circle zooms into frame
Large light blue circle oscillates between two relatively large radii as location is
calculated
Large light blue circle zooms into small darker blue circle on the user's location
Although this may be simplifying the process slightly, I think it's a good place to start and more complex/detailed functionality can be added with relative ease (i.e. the small dark circle pulsing as larger circle converges on it.)
The first thing we need is a custom CALayer subclass with a custom property for our outer large light blue circles radius:
#import <QuartzCore/QuartzCore.h>
#interface CustomLayer : CALayer
#property (nonatomic, assign) CGFloat circleRadius;
#end
and the implementation:
#import "CustomLayer.h"
#implementation CustomLayer
#dynamic circleRadius; // Linked post tells us to let CA implement our accessors for us.
// Whether this is necessary or not is unclear to me and one
// commenter on the linked post claims success only when using
// #synthesize for the animatable property.
+ (BOOL)needsDisplayForKey:(NSString*)key {
// Let our layer know it has to redraw when circleRadius is changed
if ([key isEqualToString:#"circleRadius"]) {
return YES;
} else {
return [super needsDisplayForKey:key];
}
}
- (void)drawInContext:(CGContextRef)ctx {
// This call is probably unnecessary as super's implementation does nothing
[super drawInContext:ctx];
CGRect rect = CGContextGetClipBoundingBox(ctx);
// Fill the circle with a light blue
CGContextSetRGBFillColor(ctx, 0, 0, 255, 0.1);
// Stoke a dark blue border
CGContextSetRGBStrokeColor(ctx, 0, 0, 255, 0.5);
// Construct a CGMutablePath to draw the light blue circle
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddArc(path, NULL, rect.size.width / 2,
rect.size.height / 2,
self.circleRadius, 0, 2 * M_PI, NO);
// Fill the circle
CGContextAddPath(ctx, path);
CGContextFillPath(ctx);
// Stroke the circle's border
CGContextAddPath(ctx, path);
CGContextStrokePath(ctx);
// Release the path
CGPathRelease(path);
// Set a dark blue color for the small inner circle
CGContextSetRGBFillColor(ctx, 0, 0, 255, 1.0f);
// Draw the center dot
CGContextBeginPath (ctx);
CGContextAddArc(ctx, rect.size.width / 2,
rect.size.height / 2,
5, 0, 2 * M_PI, NO);
CGContextFillPath(ctx);
CGContextStrokePath(ctx);
}
#end
With this infrastructure in place, we can now animate the radius of the outer circle with ease b/c CoreAnimation will take care of the value interpolations as well as redraw calls. All we have to do his add an animation to the layer. As a simple proof of concept, I chose a simple CAKeyframeAnimation to go through the 3 stage animation:
// In some controller class...
- (void)addLayerAndAnimate {
CustomLayer *customLayer = [[CustomLayer alloc] init];
// Make layer big enough for the initial radius
// EDIT: You may want to shrink the layer when it reacehes it's final size
[customLayer setFrame:CGRectMake(0, 0, 205, 205)];
[self.view.layer addSublayer:customLayer];
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"circleRadius"];
// Zoom in, oscillate a couple times, zoom in further
animation.values = [NSArray arrayWithObjects:[NSNumber numberWithFloat:100],
[NSNumber numberWithFloat:45],
[NSNumber numberWithFloat:50],
[NSNumber numberWithFloat:45],
[NSNumber numberWithFloat:50],
[NSNumber numberWithFloat:45],
[NSNumber numberWithFloat:20],
nil];
// We want the radii to be 20 in the end
customLayer.circleRadius = 20;
// Rather arbitrary values. I thought the cubic pacing w/ a 2.5 second pacing
// looked decent enough but you'd probably want to play with them to get a more
// accurate imitation of the Maps app. You could also define a keyTimes array for
// a more discrete control of the times per step.
animation.duration = 2.5;
animation.calculationMode = kCAAnimationCubicPaced;
[customLayer addAnimation:animation forKey:nil];
}
The above is a rather "hacky" proof of concept as I am not sure of the specific way in which you intend to use this effect. For example, if you wanted to oscillate the circle until data was ready, the above wouldn't make a lot of sense because it will always oscillate twice.
Some closing notes:
Again, I am not sure of your intent for this effect. If, for
example, you're adding it to an MKMapView, the above may require
some tweaking to integrate with MapKit.
The linked post suggests the above method requires the version of CoreAnimation in iOS 3.0+ and OS X 10.6+
Speaking of the linked post (as I did often), much credit and thanks to Ole Begemann who wrote it and did a wonderful job explaining custom properties in CoreAnimation.
EDIT: Also, for performance reasons, you're probably going to want to make sure the layer is only as big as it needs to be. That is, after your done animating from the larger size, you may want to scale the size down so you're only using/drawing as much room as necessary. A nice way to do this would be just to find a way animate the bounds (as opposed to circleRadius) and perform this animation based the size interpolation but I've had some trouble implementing that (perhaps someone could add some insight on that subject).
Hope this helps,
Sam
Add this to your map object:
myMap.showsUserLocation = TRUE;

how to draw new lines without old ones disappering?

I want to create a simple tool for drawing. The purpose is to draw a line that follows the accelerometer of the iPhone & iPad, so if the user tilts the device a line will be draw in the direction the device was moved.
I am able to register acceleration and drawing lines. My problem is that as soon as I draw a line the old one disappears. One possible solution would be to save to points already drawn and then re-draw everything, but I would think there are better solutions?
All help is appreciated!
My drawRect is at the moment like this:
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 20.0);
CGContextSetStrokeColorWithColor(context, [UIColor yellowColor].CGColor);
CGContextMoveToPoint(context, fromPoint.x, fromPoint.y);
CGContextAddLineToPoint(context, toPoint.x, toPoint.y);
CGContextStrokePath(context);
}
A different method is responsible for refreshing. This method is also called from the uiviewcontroller with certain intervals. Right now it shows a "trail" (or what I should call it) in the direction the device was moved. Not exactly what I am looking for:
- (void)drawNewLine:(CGPoint)to {
// calculate trail behind current point
float pointDifferenceX = ((toPoint.x - to.x) * 9);
float pointDifferenceY = ((toPoint.y - to.y) * 9);
fromPoint = CGPointMake(toPoint.x + pointDifferenceX, toPoint.y + pointDifferenceY);
toPoint = to;
[self setNeedsDisplay];
}
I can think of two options:
Either save all points and redraw the lines whenever the screen needs to be refreshed (as you mentioned)
Draw the lines into an off-screen pixelmap and refresh the screen from there
In either case, respect the Hollywood principle: Don't call, you will be called. That means don't just draw to the screen but wait for until drawRect: of your UIView is called. (You can trigger this by calling setNeedsDisplay.)