iOS custom scrollbar for UIScrollView - ios

iOS scrollbars for a UIScrollView usually hide after a brief delay, but I want to the scrollbars in my app to show all the time like in this picture:
Do you have any Idea how to implement this feature? Can I use a custom UISlider for this? If you can provide answers, please do so in simple English because it's not my native language. Thank you!

There is no direct way to show scrollbar permanent.
You can do this by UISlider and UIImageView.
1) Add UImage View for Vertical line.
UIImageView *scrollLineImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"scroll_1-1.png"]];
scrollLineImageView.frame = CGRectMake(970,160,2,254);
[self.view addSubview:scrollLineImageView];
2) Add UISlider and transform to UISlider vertical .UISlider height should be your scroll view height.
CGAffineTransform trans = CGAffineTransformMakeRotation(M_PI * 0.5);
self.scrollViewSlider.transform = trans;
self.scrollViewSlider.frame = CGRectMake(972.5,189,0, self.textScrollView.frame.size.height);
Set Slider minimum value to 0 and maximum value to scrollView content height.
self.scrollViewSlider.minimumValue = 0.0;
self.scrollViewSlider.maximumValue = self.textScrollView.contentSize.height;
3) Set UISlider Thumb Image
[self.scrollViewSlider setThumbImage:[UIImage imageNamed:#"scroll_circle.png"] forState:UIControlStateNormal];
4) Clear Minimum and Maximum track Image.
UIImage *clearImage = [[UIImage alloc] init];
[self.scrollViewSlider setMinimumTrackImage:clearImage forState:UIControlStateNormal];
[self.scrollViewSlider setMaximumTrackImage:clearImage forState:UIControlStateNormal];
5) ScrollView Delegate Function to scroll slider
self.scrollViewSlider.value=scrollView.contentOffset.y;
I hope this helps you to show Scroll Bar Permanent.

Related

UIButton background image used for animation not aligned across devices

I have a UIButton backgroundImage that I use to display a weather condition image when the loading is complete. I also create a UIImageView that replaces the UIButton to animate a series of images as a progress indicator.
My question: How can fix this animated UIImageView x-axis misalignment across multiple screen sizes?
Here's what the sequence looks like on 4.7" iPhone, the red box indicates the image I'm talking about:
First, the UIImageView animating as a progress indicator (imagine it spinning, alignment is correct)
Second, the download complete, the progress indicator replaced by a UIButton with a backgroundImage:
Third, the UIImageView animating on 4" iPhone (note misalignment on x-axis):
Fourth, the download complete, UIButton replaces it, aligned correctly:
Here's how the UIImageView *progressIndicator is configured.
Note that conditionButton is the UIButton with backgroundImage of the weather condition:
self.progressIndicator = [[UIImageView alloc] initWithFrame:self.conditionButton.frame];
self.progressIndicator.contentMode = UIViewContentModeCenter;
self.progressIndicator.animationImages = #[...long series of images...];
self.progressIndicator.animationDuration = 0.5f;
[self.conditionButton setBackgroundImage:[UIImage imageNamed:#"empty.png"] forState:UIControlStateNormal];
[self.progressIndicator startAnimating];
[self.view addSubview:self.progressIndicator];
I'm pretty sure the issue is with
self.progressIndicator = [[UIImageView alloc] initWithFrame:self.conditionButton.frame];
But I'm not sure how to resolve this.
The same problem occurs when I switch to 5.5" iPhone. I have no Auto Layout warnings, and the constraints that apply to the conditionButton are:
Align Center X to superview
Width = 94
Height = 94
Bottom and Top space to nearest neighbor = default
Any help would be greatly appreciated!

Scrolling UILabel like a marquee in a subview

I have a UILabel in the main view with text - "Very Very long text". The proper width to this would be 142, but i've shortened it to 55.
Basically I want to implement a marquee type scroll, so I wrote code to add it onto a subview and animate it within the bounds of that view.
CODE --
CGRect tempLblFrame = _lblLongText.frame;
UIView *lblView = [[UIView alloc] initWithFrame:tempLblFrame];
//Add label to UIView at 0,0 wrt to new UIView
tempLblFrame.origin.x = 0;
tempLblFrame.origin.y = 0;
[_lblLongText setFrame:tempLblFrame];
[_lblLongText removeFromSuperview];
[lblView addSubview:_lblLongText];
//SetClipToBounds so that if label moves out of bounds of its superview, it wont be displayed
[lblView setClipsToBounds:YES];
[lblView setBackgroundColor:[UIColor cyanColor]];
[self.view addSubview:lblView];
After this I get this output on the simulator -->
The problem occurs when i try the Animation with this code -
tempLblFrame.origin.x = -_lblLongText.intrinsicContentSize.width;
[UIView animateWithDuration:2.0 delay:1.0 options:UIViewAnimationOptionCurveLinear
animations:^{
[_lblLongText setFrame:tempLblFrame];
}
completion:^(BOOL finished) {
NSLog(#"completed");
}];
I was hoping I would see the entire "Very Very long text", rather only "Very..." scrolls from left to right.
To solve this I added one line of code --
//Add label to UIView at 0,0 wrt to new UIView
tempLblFrame.origin.x = 0;
tempLblFrame.origin.y = 0;
tempLblFrame.size.width = _lblLongText.intrinsicContentSize.width; //THIS LINE WAS ADDED
[_lblLongText setFrame:tempLblFrame];
[_lblLongText removeFromSuperview];
[lblView addSubview:_lblLongText];
I thought the full text will be set inside the newly added UIView and it would scroll properly. But running in the simulator gave me this --
And again, only "Very..." was scrolling from left to right.
What am I doing wrong? Please help!!
EDIT
Apparently the culprit was AutoLayout.
I have no clue why, but once I unchecked "Use Autolayout" for the view
in the XIB, everything started working as expected. Setting
tempLblFrame.origin.x = -_lblLongText.intrinsicContentSize.width; was
working properly and so was the scroll.
Any explanation on this!!?
This question is possibly Duplicate of.
Although there is nice code snippet written by Charles Powell for MarqueeLabel,
also take a look at This link.
I hope this will help you and will save your time by giving a desired output.
Make the UILabel the width (or longer) of the text and the UIView the scroll area you want to see. Then set the UIView's clipToBounds to YES (which you are doing). Then when you animate left to right you will only see the the text the width of the UIView, since it is cutting any extra subviews. Just make sure you scroll the entire length of the UILabel.
Right now you are setting the view and label's height and width to the same thing. This is why you are getting clipped text, not a clipped label.
You add In your view scrollview and add this label in your scroll view .Use this code
scroll.contentSize =CGSizeMake(100 *[clubArray count],20);
NSString *bname;
bname=#"";
for(int i = 0; i < [clubArray count]; i++)
{
bname = [NSString stringWithFormat:#"%# %# ,",bname,[[clubArray objectAtIndex:i] objectForKey:#"bottle_name"]];
[bname retain];
}
UILabel *lbl1 = [[UILabel alloc] init];
[lbl1 setFrame:CGRectMake(0,5,[clubArray count]*100,20)];
lbl1.backgroundColor=[UIColor clearColor];
lbl1.textColor=[UIColor whiteColor];
lbl1.userInteractionEnabled=YES;
[scroll addSubview:lbl1];
lbl1.text= bname;
This is implemented code.Thanks
Apparently the culprit was AutoLayout.
I have no clue why, but once I unchecked "Use Autolayout" for the view in the XIB, everything started working as expected. Setting tempLblFrame.origin.x = -_lblLongText.intrinsicContentSize.width; was working properly and so was the scroll.
Still, a better explanation for this would surely help!!
EDIT: Solution with AutoLayout -
//Make UIView for Label to sit in
CGRect tempLblFrame = _lblLongText.frame;
UIView *lblView = [[UIView alloc] initWithFrame:tempLblFrame];
//#CHANGE 1 Removing all constraints
[_lblLongText removeConstraints:_lblLongText.constraints];
//Add label to UIView at 0,0 wrt to new UIView
tempLblFrame.origin.x = 0;
tempLblFrame.origin.y = 0;
//Set Full length of Label so that complete text shows (else only truncated text will scroll)
tempLblFrame.size.width = _lblLongText.intrinsicContentSize.width;
//#CHANGE 2 setting fresh constraints using the frame which was manually set
[_lblLongText setTranslatesAutoresizingMaskIntoConstraints :YES];
[_lblLongText setFrame:tempLblFrame];
[_lblLongText removeFromSuperview];
[lblView addSubview:_lblLongText];

uitableview.backgroundView image dimension is compressing/distorting

I'm building an iphone app.
I have a tableview and i set a background image like so:
UIImageView * bg = [[UIImageView alloc] initWithImage:somebackgroundimage];
CGRect framebg = bg.frame;
framebg.origin.y = -64;
framebg.origin.x = 0;
framebg.size.width = 320;
framebg.size.height = 480;
[bg setFrame:framebg];
[_tblview setBackgroundView:bg];
no matter what framebg.size.width or framebg.size.height I set, the image always appears distorted or compressed with a size of maybe 320 width and 400 height. It is almost as if the app will forcefully resize the image to fit between the top navigation bar and my bottom tab bar.
How do I force tableview background image to be of 320px width by 480px height?
Also it seems the origin.y and origin.x aren't being respected either.
I know this question is a bit old, but I thought i would share what I was able to use to get around a similar issue (using setContentMode for the image view):
UIImageView *bg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"background.png"]];
[bg setContentMode:UIViewContentModeScaleAspectFit];
self.tableView.backgroundView = bg;
Hope this helps.

Custom MPVolumeView Thumb Image not vertically centered since iOS 5.1

I'm building an application that needs an MPVolumeView to control the volume. It worked perfectly before iOS 5.1 but since the 5.1 update the thumb image is no longer vertically centered. I tried a few things like changing imagine dimensions, resizing my views (and slider) but nothing seems to work, the thumb is just not vertically centered anymore. The only way i get a centered thumb is if i use the default iOS one.
I tried adding a UISlider to another view with the exact min, max and thumb image and that one is centered fine.
Here is the code for the MPVolumeView:
MPVolumeView *volumeView;
volumeView = [[[MPVolumeView alloc] initWithFrame:volumeViewHolder.bounds] autorelease];
[volumeViewHolder addSubview:volumeView];
UIView *volumeViewSlider;
for (UIView *view in [volumeView subviews])
{
if ([[[view class] description] isEqualToString:#"MPVolumeSlider"])
{
volumeViewSlider = view;
}
}
[(UISlider *)volumeViewSlider setThumbImage:sliderHandleIcon forState:UIControlStateNormal];
[(UISlider *)volumeViewSlider setMinimumTrackImage:leftTrackImage forState:UIControlStateNormal];
[(UISlider *)volumeViewSlider setMaximumTrackImage:rightTrackImage forState:UIControlStateNormal];
volumeViewHolder is just a UIView thats 153x33. I put the thumb in green in the screenshot.
Maybe a better solution:
User a bigger image with a transparent border on the bottom. Should be around 10px for Retina Displays.
the same problem i resolved in one project. Must be set color of left part and right part with alpha = 0 -it means transparent all slider without thumb (without moovable part of it). After we must create custom view for line of slider, without thumb. In this view any colored part may be shifted as you want, upper or below, left or right. It obtained using the defined y for your ocassion:
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(x,y,width, height)];
And add the slider to this line as subview. Resulted view will be slider. For example:
UISlider *ourSlider = ...;
//initialise UISlider
ourSlider.minimumTrackTintColor = [UIColor colorWithRed:0 green:122.0f/255.0f blue:1 alpha:0];
ourSlider.minimumTrackTintColor = [UIColor colorWithRed:0 green:122.0f/255.0f blue:1 alpha:0];
UIView *lineOfSliderWithoutThumb = ... ;
// creation it
[lineOfSliderWithoutThumb addSubview:ourSlider];
//after this lineOfSliderWithoutThumb is the our custom uislider.
Note: colors there are used as default slider colors of left and right sides of UISlider.

How do I prevent a button's background image from stretching?

I'm allocating a UIButtonTypeCustom to a UIView with a background image that is smaller than the button's frame.
Reason why the image is smaller is because I'm trying to add more of a "target area" for the UIButton. However, the image is being scaled to the full size of the frame, rather than just being the image's size.
I have tried setting the UIButton and UIButton's imageView's contentMode property to UIViewContentModeScaleAspectFit, but no luck, the image still gets stretched out.
Is there a way to do what I'm trying to do programmatically?
Thanks in advance!
A lot of people make the same mistake you do in regards to button images and then jump through hoops trying to make the button behave as they expect it to. Let's clear this up once and for all:
A UIButton has two types of images it can display -- a foreground image and a background image. The background image for a button is expected to replace the button's background texture. As such, it makes sense that it stretches to fill the entire background. However, the button's foreground image is expected to be an icon that may or may not display alongside text; it will not stretch. It may shrink if the frame is smaller than the image, but it will not stretch. You can even set the alignment of the foreground image using the Control alignment properties in Interface Builder.
A button's foreground and background image can be set in code like this:
// stretchy
[self setBackgroundImage:backgroundImage forState:UIControlStateNormal];
// not stretchy
[self setImage:forgroundImage forState:UIControlStateNormal];
You don't have access to the background imageView, but there is fully working workaround:
EDIT: There is an even better workaround then what I posted originally.
You can create a UIImage from any color, and call -setBackgroundImage:forState.
See bradley's answer, here:
https://stackoverflow.com/a/20303841/1147286
Original answer:
Instead of calling -setBackgroundImage:forState:, create a new UIImageView and add it as a subview of the button.
UIImageView *bgImageView = [[UIImageView alloc] initWithImage:img];
bgImageView.contentMode = UIViewContentModeScaleAspectFit;
[bgImageView setFrame:CGRectMake(0, 0, videoButton.frame.size.width, videoButton.frame.size.height)];
bgImageView.tag = 99;
[yourButton addSubview:bgImageView];
[yourButton bringSubviewToFront:yourButton.imageView];
Create the imageview
Set the content mode and frame
I also set a recognizable tag, so that when the screen rotates I can easily find my custom imageView in the button's subviews and reset its frame
Add it as a subview to the button
Bring the frontal imageView of the button to the front so our custom imageView doesn't overlap it
When the button needs to rotate just find the imageView by its tag and reset its frame:
UIImageView *bgImageView = (UIImageView *)[button viewWithTag:99];
[bgImageView setFrame:CGRectMake(0, 0, newWidth, newHeight)];
The cleanest and easiest way it probably to use the title insets of the button.
You set your image as the button image, and then you change the left title inset to match minus the width of your image:
myButton.titleEdgeInsets = UIEdgeInsetsMake(0, -myImage.width, 0, 0)
This will move the text back where it was before the image was added to its left. You can also use this value to add some padding to you button.
Stumbled on this problem too.
Adding image programmatically, as memmons thoroughly explained, did not help:(
I had a button 100x40 and image 100x100, it would appear squeezed, not fitted, as one would infer from "Aspect Fit" option. Actually, non of those view options had an effect.
I just had to rescale it so it would fit on a button, then use setImage:
UIImage *img=[UIImage imageNamed:#"myimage.png"];
CGImageRef imgRef = [img CGImage];
CGFloat imgW = CGImageGetWidth(imgRef);
CGFloat imgH = CGImageGetHeight(imgRef);
CGFloat btnW = myBttn.frame.size.width;
CGFloat btnH = myBttn.frame.size.height;
//get lesser button dimension
CGFloat minBtn=btnW;
if (btnW>btnH) {
minBtn=btnH;
}
//calculate scale using greater image dimension
CGFloat scl=imgH/minBtn;
if (imgW>imgH) {
scl=imgW/minBtn;
}
//scale image
UIImage *scaledImage = [UIImage imageWithCGImage:[img CGImage] scale:(img.scale * scl) orientation:(img.imageOrientation)];
//clean up
UIGraphicsEndImageContext();
//set it on a button
[myBttn setImage:scaledImage forState:UIControlStateNormal];
It is simple as:
ImageBtn.imageView?.contentMode = .scaleAspectFit
ImageBtn.setImage(chosenImage, for: .normal)
Another consideration is the BaseLine constraint. If your buttons have this constraint set (depicted as a horizontal or vertical line through multiple controls on your layout), it will cause your images to stretch without stretching the underlying button control. If your button is otherwise properly constrained (leading/trailing and top/bottom spaces, and etc...) removing the BaseLine constraint should have no impact on the layout, while allowing the foreground image to scale properly to the underlying button shape.
Answerbot answers the question with what is proper and correct to do. Don't fight the OS and use things as intended is always good advice. However, sometimes you need to break the rules.
I was able to mask the enlarged background image (not prevent it) by overlaying it with a black CAlayer then overlaying again with a properly resized image CAlayer. This was all done by creating a subclass of UIButton and overwriting the setHighlighted method.
NEED CODE?
- (void)setHighlighted:(BOOL)highlighted
{
super.highlighted = highlighted;
//
//Whenever an image needs to be highlighted, create a dimmed new image that is correctly sized. Below it is a englarged stretched image.
//
if (highlighted != _previousHighlightedSate)
{
_previousHighlightedSate = highlighted;
if (highlighted)
{
//Create a black layer so image can dim
_blackLayer = [CALayer layer];
_blackLayer.bounds = self.bounds;
CGRect rect = _blackLayer.bounds;
rect.size.width = rect.size.width*2;
rect.size.height = rect.size.height*2;
_blackLayer.bounds = rect;
_blackLayer.backgroundColor = [[UIColor blackColor] CGColor];
//create image layer
_nonStretchImageLayer = [CALayer layer];
_nonStretchImageLayer.backgroundColor = [UIColor blackColor].CGColor;
_nonStretchImageLayer.bounds = CGRectMake(0 , 0, self.bounds.size.width, self.bounds.size.height);
_nonStretchImageLayer.frame = CGRectMake(0 , 0, self.bounds.size.width, self.bounds.size.height);
_nonStretchImageLayer.contentsGravity = kCAGravityResizeAspect;//default is to resize
_nonStretchImageLayer.contents = (id)self.imageView.image.CGImage;
_nonStretchImageLayer.opacity = 0.5;
//add layers to image view
[self.imageView.layer addSublayer:_blackLayer];
[self.imageView.layer addSublayer:_nonStretchImageLayer];
}
else
{
//remove from image view
[_blackLayer removeFromSuperlayer];
[_nonStretchImageLayer removeFromSuperlayer];
//nil them out.
_blackLayer = nil;
_nonStretchImageLayer = nil;
}
}
Inspiration for this work around came from here
I guess the easiest solution is to use UIImage's resizableImageWithCapInsets method. Use UIEdgeInsetsMake to configure the free spaces.
might help someone
button.subviews.first?.contentMode = .scaleAspectFit
Swift version of Zoltán Matók answer
Just a copy of my code using SnapKit to do auto layout and syntatic sugar Then library for initilizations, it should work similar for normal Apples way of programatic layout.
let backButton = UIButton(type: .custom).then { (button) in
let image = UIImage(named: "backButtonIcon")?.withRenderingMode(.alwaysOriginal)
let imageView = UIImageView(image: image)
button.addSubview(imageView)
imageView.snp.makeConstraints { (make) in
make.center.equalTo(button.snp.center)
}
button.bringSubviewToFront(imageView)
button.contentMode = .scaleAspectFit
button.backgroundColor = .clear
button.isUserInteractionEnabled = true
button.isEnabled = true
button.imageView?.contentMode = .scaleAspectFit
button.imageView?.snp.makeConstraints({ (make) in
make.height.width.equalTo(24)
})
button.snp.makeConstraints { (make) in
make.height.width.equalTo(24)
}
}
You can use uibutton.imageView.contentMode for no stretching:
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(posX, posY, widthButton, heightButton);
[button setTitle:#"" forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:#"imageNamed"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:#"imageNamedHighlighted"] forState:UIControlStateHighlighted];
button.imageView.contentMode = UIViewContentModeScaleAspectFit;
[button addTarget:self action:#selector(functionMenu:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview: button];
What you need to do is add your image as a UIImageView.
Than add a button with transperent background (UIColor ClearColor) on top of it with your desired width and height.

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