I have a UIWebView with a contentEditable div in order to implement some kind of rich text editor. I need to trimm the copy & cut options in the UIMenuController that appears in the web view once the user selects any piece of text.
There seems to be a lot of solutions around the web, but for some reason, non of them applies for my scenario.
I've subclassed the UIWebView and implemented the canPerformAction:(SEL)action withSender: to remove the copy and cut, but once the user chooses "Select" or "Select All", a new menu appears, and apparently, the web view does not intercept this action and the canPerform method is not being called.
Is there a way to trimm actions for this cases?
I will adapt another answer of mine for your case.
The canPerformAction: is actually called on the internal UIWebDocumentView instead of the UIWebView, which you cannot normally subclass. With some runtime magic, it's possible.
We create a class which has one method:
#interface _SwizzleHelper : UIView #end
#implementation _SwizzleHelper
-(BOOL)canPerformAction:(SEL)action
{
//Your logic here
return NO;
}
#end
Once you have a web view which you want to control the actions of, you iterate its scroll view's subviews and take the UIWebDocumentView class. We then dynamically make the superclass of the class we created above to be the subview's class (UIWebDocumentView - but we cannot say that upfront because this is private API), and replace the subview's class to our class.
#import "objc/runtime.h"
-(void)__subclassDocumentView
{
UIView* subview;
for (UIView* view in self.scrollView.subviews) {
if([[view.class description] hasPrefix:#"UIWeb"])
subview = view;
}
if(subview == nil) return; //Should not stop here
NSString* name = [NSString stringWithFormat:#"%#_SwizzleHelper", subview.class.superclass];
Class newClass = NSClassFromString(name);
if(newClass == nil)
{
newClass = objc_allocateClassPair(subview.class, [name cStringUsingEncoding:NSASCIIStringEncoding], 0);
if(!newClass) return;
Method method = class_getInstanceMethod([_SwizzleHelper class], #selector(canPerformAction:));
class_addMethod(newClass, #selector(canPerformAction:), method_getImplementation(method), method_getTypeEncoding(method));
objc_registerClassPair(newClass);
}
object_setClass(subview, newClass);
}
Related
I have made a view in the application that shows a UITableView. It will be full of results (obviously) almost all the time, however when it does not have any results I want to show another view that inform the user about how he/she could populate the table.
I want to design that view in the interfacebuilder. I will have to check in the code whether the datasource is empty or not to toggle between the two different nibs. How do I instantiate and configure a view made in Interfacebuilder?
The easies way to do this is by adding the view in xib normally and make it visible
Design your both views, the table view and the other view, give the tableView a tag of 111 for example and give the otherview another tag 222 for example
Now in viewDidLoad
Get both the views
UIView *noDataView = [self.view viewWithTag:222];
UITableView *tableView = [self.view viewWithTag:111];
//Hide both of them or only the noDataView until you know if you have data from the dataSource or not
Check for your data source
//hasElements do you have any element to show?
if(hasElements)
{
noDatView.hidden = YES;
tableView.hidden = NO;
}
else
{
noDatView.hidden = NO;
tableView.hidden = YES;
}
You can load nib file based on condition.You can write category as follows:
self.view = (UIView *)[self loadNib:#"SecondView" inPlaceholder:self.view];
- (UIView *)viewFromNib:(NSString *)nibName
{
NSArray *xib = [[NSBundle mainBundle] loadNibNamed:nibName owner:self options:nil];
for (id view in xib) { // have to iterate; index varies
if ([view isKindOfClass:[UIView class]]) return view;
}
return nil;
}
- (UIView *)loadNib:(NSString *)nibName inPlaceholder:(UIView *)placeholder
{
UIView *nibView = [self viewFromNib:nibName];
[nibView setFrame:placeholder.frame];
self.view = nibView;
//[self.view insertSubview:nibView aboveSubview:placeholder];
//[placeholder removeFromSuperview];
return nibView;
}
The other answers give you possible technical solutions but I would propose that if you are using the standard Apple design guidelines, you probably don't even need to worry about it. For instance, somewhere on your screen you should have a bar button item with the identifier "Add" (which shows the plus icon). Then rather than giving a long (often poorly localised) description of how to add items, just have a header for an empty section which says "No items" replacing items with whatever pluralised noun is appropriate for your table's items. For example, for an Archery related app I am working on:
Notice how the Edit button is currently disabled too, thus no explanation is needed as the only thing they can do at this point is tap the Add button (screenshots on the Appstore will have shown them what they can expect to see after this point).
I want to make horizontal paging in my app.
I have big text, which placed in UITextView, but I want to make horizontal paging, like iBooks or bookmate.
Do you have any solution or idea?
Have a look at the new (iOS 5) class UIPageViewController. For the iBooks page curl effect, try using
[controller initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options:nil];
You can then set the view controllers using setViewControllers:direction:animated:completion:. For more reference for this class, visit the UIPageViewController Class Reference.
Use this handy class called PagedView which manages a paging scroll view as well as view loading/unloading and reuse for you.
You have to implement two delegate methods to get it working:
- (NSUInteger)numberOfPagesInPagedView:(PagedView *)view;
- (UIView *)pagedView:(PagedView *)view viewForPageAtIndex:(NSUInteger)page;
They will look familiar if you've ever used UITableView. In numberOfPagesInPagedView: you just have to return the number of pages you want to display.
- (NSUInteger)numberOfPagesInPagedView:(PagedView *)view
{
// return the number of pages in the paging view
return 10;
}
In pagedView:viewForPageAtIndex: you have to return a view for a specific page index. You can reuse the views by sending the dequeueReusableViewWithIdentifier: message to the paged view.
- (UIView *)pagedView:(PagedView *)pagedView viewForPageAtIndex:(NSUInteger)page
{
static NSString *reuseIdentifier = #"PageIdentifier";
UIView *view = [pagedView dequeueReusableViewWithIdentifier:reuseIdentifier];
if(view == nil) {
view = [[[MyPageView alloc] initWithFrame:view.bounds] autorelease];
}
// add contents specific to this page index to the view
return view;
}
In order to get view reuse working, your UIView subclass (MyPageView) should conform to the ReusableObject protocol and implement reuseIdentifier (in this case you would return #"PageIdentifier").
I have used this class in a number of projects and it works pretty well.
UIScrollView with pageEnabled turned on?
You can use a UIWebView (subclass of UIScrollView) for your horizontal paging needs.
For it to work, you'd need to split the NSString that you use to store your text, depending on the size (and height) of your web view.
Store the split NSString into an NSArray, and then depending on user swipe, load up the correct 'page' (array index) and display with animation.
Hope that helps.
I'm using TTLauncherView as a sort of home screen for my app and I only have one page's worth of icons. How can I make it so the TTLauncherView won't let you drag icons to "the next page"? I want to set a maximum number of pages (in this case one.)
(EDIT: long story short, I subclassed beginEditing, see the answer below.)
I see where why it adds an extra page when beginEditing is called, but I don't want to edit the framework code. (That makes it hard to update to newer versions.) I'd also prefer not to subclass and override that one method, if I have to rely on how it's implemented. (I'm not against subclassing or adding a category if it's clean.)
I tried setting scrollView.scrollEnabled to NO in the callback method launcherViewDidBeginEditing in my TTLauncherViewDelegate, but that doesn't work while it's in editing mode and I don't know why.
I tried adding a blocker UIView to the scrollview to intercept the touch events by setting userInteractionEnabled=NO, which works OK. I still have to disable the dragging of TTLauncherItems to the next page somehow.
I also tried setting the contentSize of the scrollview to it's bounds in launcherViewDidBeginEditing, but that didn't seem to work either.
Is there a better way?
Tried to block gestures:
- (void)setLauncherViewScrollEnabled:(BOOL)scrollEnabled {
if (scrollEnabled) {
[self.scrollViewTouchInterceptor removeFromSuperview];
self.scrollViewTouchInterceptor = nil;
} else {
// iter through the kids to get the scrollview, put a gesturerecognizer view in front of it
UIScrollView *scrollView = [launcherView scrollViewSubview];
self.scrollViewTouchInterceptor = [UIView viewWithFrame:scrollView.bounds]; // property retains it
UIView *blocker = self.scrollViewTouchInterceptor;
[scrollView addSubview:scrollViewTouchInterceptor];
[scrollView sendSubviewToBack:scrollViewTouchInterceptor];
scrollViewTouchInterceptor.userInteractionEnabled = NO;
}
}
For reference: TTLauncherView.m:
- (void)beginEditing {
_editing = YES;
_scrollView.delaysContentTouches = YES;
UIView* prompt = [self viewWithTag:kPromptTag];
[prompt removeFromSuperview];
for (NSArray* buttonPage in _buttons) {
for (TTLauncherButton* button in buttonPage) {
button.editing = YES;
[button.closeButton addTarget:self action:#selector(closeButtonTouchedUpInside:)
forControlEvents:UIControlEventTouchUpInside];
}
}
// Add a page at the end
[_pages addObject:[NSMutableArray array]];
[_buttons addObject:[NSMutableArray array]];
[self updateContentSize:_pages.count];
[self wobble];
if ([_delegate respondsToSelector:#selector(launcherViewDidBeginEditing:)]) {
[_delegate launcherViewDidBeginEditing:self];
}
}
I think overriding beginEditing in TTLauncherView is your best bet. Since you'd only really be touching one method (and only a few lines in that method), upgrading it when the time comes shouldn't be too bad. Since that method explicitly adds the extra page, I'm not sure how you'd get around it w/o editing that specific piece of code
As Andrew Flynn suggested in his answer, I was able to make it work by subclassing and overriding the beginEditing method to remove the extra page TTLauncherView adds when it goes into editing mode.
One problem I'm having is I can't figure out how to remove the warning I get for calling the (private) method updateContentSize on my subclass. I tried casting it to id, but that didn't remove the warning. Is it possible?
edit: I was able to remove the warning by using performSelector to send the message to the private class. (I had previously create a category method performSelector:withInt that wraps NSInvocation so that I can pass primitives via performSelector methods, which makes this very convenient.)
// MyLauncherView.h
#interface MyLauncherView : TTLauncherView {
NSInteger _maxPages;
}
#property (nonatomic) NSInteger maxPages;
#end
// MyLauncherView.m
#implementation MyLauncherView
#synthesize maxPages = _maxPages;
- (void)beginEditing {
[super beginEditing];
// ignore unset or negative number of pages
if (self.maxPages <= 0) {
return;
}
// if we've got the max number of pages, remove the extra "new page" that is added in [super beginEditing]
if ([_pages count] >= self.maxPages ) {
[_pages removeLastObject];
[self updateContentSize:_pages.count]; // this has a compiler warning
// I added this method to NSObject via a category so I can pass primitives with performSelector
// [self performSelector:#selector(updateContentSize:) withInt:_pages.count waitUntilDone:NO];
}
}
I have noticed, in one of my views in an iPad app I am building the next button on the keyboard goes through all the UITextFields from left to right down the screen.
Is it possible somehow to make it go top to bottom then right, top to bottom?
So say I have to two long columns of text fields, I wan to go top to bottom not left to right, make sense?
Any help appreciated, thanks.
I don't think there is a way through IB, but you can do this way in code. You're not actually tabbing, you'd be using the return key.
Put this in your UITextField's delegate:
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
BOOL shouldChangeText = YES;
if ([text isEqualToString:#"\n"]) {
// Find the next entry field
BOOL isLastField = YES;
for (UIView *view in [self entryFields]) {
if (view.tag == (textView.tag + 1)) {
[view becomeFirstResponder];
isLastField = NO;
break;
}
}
if (isLastField) {
[textView resignFirstResponder];
}
shouldChangeText = NO;
}
return shouldChangeText;
}
Found here: http://iphoneincubator.com/blog/tag/uitextfield
You'll want to implement UITextFieldDelegate's - (BOOL)textFieldShouldReturn:(UITextField *)textField method. An example of how to use this method to control the order is in this question.
I would like to elaborate on #sprocket's answer addressing the same issue. Just because something works out of the box doesn't mean you should stop thinking about a better way -- or even the right way -- of doing something. As he noticed the behavior is undocumented but fits our needs most of the time.
This wasn't enough for me though. Think of a RTL language and tabs would still tab left-to-right, not to mention the behavior is entirely different from simulator to device (device doesn't focus the first input upon tab). Most importantly though, Apple's undocumented implementation seems to only consider views currently installed in the view hierarchy.
Think of a form in form of (no pun intended) a table view. Each cell holds a single control, hence not all form elements may be visible at the same time. Apple would just cycle back up once you reached the bottommost (on screen!) control, instead of scrolling further down. This behavior is most definitely not what we desire.
So here's what I've come up with. Your form should be managed by a view controller, and view controllers are part of the responder chain. So you're perfectly free to implement the following methods:
#pragma mark - Key Commands
- (NSArray *)keyCommands
{
static NSArray *commands;
static dispatch_once_t once;
dispatch_once(&once, ^{
UIKeyCommand *const forward = [UIKeyCommand keyCommandWithInput:#"\t" modifierFlags:0 action:#selector(tabForward:)];
UIKeyCommand *const backward = [UIKeyCommand keyCommandWithInput:#"\t" modifierFlags:UIKeyModifierShift action:#selector(tabBackward:)];
commands = #[forward, backward];
});
return commands;
}
- (void)tabForward:(UIKeyCommand *)command
{
NSArray *const controls = self.controls;
UIResponder *firstResponder = nil;
for (UIResponder *const responder in controls) {
if (firstResponder != nil && responder.canBecomeFirstResponder) {
[responder becomeFirstResponder]; return;
}
else if (responder.isFirstResponder) {
firstResponder = responder;
}
}
[controls.firstObject becomeFirstResponder];
}
- (void)tabBackward:(UIKeyCommand *)command
{
NSArray *const controls = self.controls;
UIResponder *firstResponder = nil;
for (UIResponder *const responder in controls.reverseObjectEnumerator) {
if (firstResponder != nil && responder.canBecomeFirstResponder) {
[responder becomeFirstResponder]; return;
}
else if (responder.isFirstResponder) {
firstResponder = responder;
}
}
[controls.lastObject becomeFirstResponder];
}
Additional logic for scrolling offscreen responders visible beforehand may apply.
Another advantage of this approach is that you don't need to subclass all kinds of controls you may want to display (like UITextFields) but can instead manage the logic at controller level, where, let's be honest, is the right place to do so.
I'm trying to create this sort of "pop up action sheet" view similar to the in-call view in iPhone's phone app.
I believe this is a custom view, since I can't seem to find this in any apple references. But somehow the Google app and Discover app both have this view and look awfully similar (I've attached the images below).
So is there some kind of library/tutorial/sample code out there that can help me make something like this?
Thanks.
alt text http://a1.phobos.apple.com/us/r1000/018/Purple/e1/23/02/mzl.uiueoawz.480x480-75.jpg
(source: macblogz.com)
alt text http://ployer.com/archives/2008/02/29/iPhone%20infringes%20call%20display%20patent-thumb-480x799.png
They all look suitably different to be custom views to me. If you just want a control like this for a single view (i.e. not a more flexible configurable container type control) it should be relatively quick & easy to knock it up in xcode & IB. I've done similar things in my apps. Steps I would take are as follows:
1) create an empty NIB file and design your control there by using UIView, UIImageView, UIButton controls etc.
2) Create a new ObjC class derived from UIView
3) Ensure the 'root' UIView object in the NIB has class type matching your ObjC UIView derived class
4) Attach IBOutlets & IBAction event handlers to your class and wire up all the button events ('Touch up inside') to your class event handler methods in IB.
5) Add a static factory function to your class to create itself from the NIB. e.g.
// Factory method - loads a NavBarView from NavBarView.xib
+ (MyCustomView*) myViewFromNib;
{
MyCustomView* myView = nil;
NSArray* nib = [[NSBundle mainBundle] loadNibNamed:#"MyCustomViewNib" owner:nil options:nil];
// The behavior here changed between SDK 2.0 and 2.1. In 2.1+, loadNibNamed:owner:options: does not
// include an entry in the array for File's Owner. In 2.0, it does. This means that if you're on
// 2.2 or 2.1, you have to grab the object at index 0, but if you're running against SDK 2.0, you
// have to grab the object at index:1.
#ifdef __IPHONE_2_1
myView = (MyCustomView *)[nib objectAtIndex:0];
#else
myView = (MyCustomView *)[nib objectAtIndex:1];
#endif
return myView;
}
6) Create and place onto your parent view as normal:
MyCustomView* myView = [MyCustomView myViewFromNib];
[parentView addSubview:myView];
myView.center = parentView.center;
With regard to the event handling, I tend to create just one button event handler, and use the passed id param to determine which button is pressed by comparing against IBOutlet members or UIView tags. I also often create a delegate protocol for my custom view class and call back through that delegate from the button's event handler.
e.g.
MyCustomViewDelegate.h:
#protocol MyCustomViewDelegate
- (void) doStuffForButton1;
// etc
#end
ParentView.m:
myView.delegate = self;
- (void) doStuffForButton1
{
}
MyCustomView.m:
- (IBAction) onButtonPressed:(id)button
{
if (button == self.button1 && delegate)
{
[delegate doStuffForButton1];
}
// or
UIView* view = (UIView*)button;
if (view.tag == 1 && delegate)
{
[delegate doStuffForButton1];
}
}
Hope that helps