A really weird issue about UITextField - uitextfield

I have a textField here, and I tap it so it become the first responder,
then I leave it without inputting anything, which i think means the textField.text remains nil.
And its delegate will go to this method:
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField {
if (textField.text == nil)
return YES;
...
}
and it just does not execute the return inside the IF!!

You can use 'isEqualToString:'
Try this
if ([textField.text isEqualToString:#""])
Or just check the length
if ([textField.text length] == 0)

Related

NSTextField with NSNumberFormatter - not allow nil value

I have a NSTextField with a NSNumberFormatter. I set the formatter with a min of 0 (because I couldn't set it to 0.01), and the style to decimal. The NSTextField has a binding on its value with a float ivar, and the action is set to "Send On Enter Only". This works just fine.
What I'd like to do is if the user tries to erase the value and either clicks off, or presses enter, I want to restore the original value before editing.
I tried:
-(void) setNilValueForKey:(NSString*) key {
if ([key compare:#"valX"] == NSOrderedSame) {
self.valX = valX;
}
}
But this doesn't set the NSTextField. I'm at a loss, any help is appreciated.
Thanks
GW
For case of erasing, Implement the following delegate method as
- (void)controlTextDidChange:(NSNotification *)notification
{
NSTextField* textfield = [notification object];
if([textfield intValue] == 0)
{
[textfield setValue:valX];
}
}
For case of pressing Enter and clicking off, implement
- (void)controlTextDidEndEditing:(NSNotification *)obj
{
NSTextField* textfield = [notification object];
[textfield setValue:valX];
}

Changing Dynamic UIView subviews with single Tap in UIGestureRecognizer Method

UPDATE:Solved issue, see below!
The situation: I have several dynamically loaded UIViews on a UIScrollView in a nib.
Expected behavior: I want to single TAP any one of the UIViews and it will change background color to indicate it was tapped. If it was already tapped it should then change back to its initial look.
I have set up a UITapGesture recognizer on each of the UIViews and here is the selector method where I am doing the behavior. I have confused myself. I apologize for the sketchy logic here (it is a ruff draft). I have set up a isTapped BOOL set to "NO" initially in the init in the file.
- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
isTapped = !isTapped;
UIView *v = gestureRecognizer.view;
NSInteger currentIndex = [studentCellArray indexOfObjectIdenticalTo:v];
if (oldIndex != currentIndex) {
isTapped = YES;
}
//check to see if obj in array then switch on/off
if ([tappedViewArray indexOfObjectIdenticalTo:v] != NSNotFound) {
oldIndex = currentIndex;
}
if (currentIndex == v.tag) {
isTapped = !isTapped;
}
if (isTapped) {
[tappedViewArray addObject:v];
[super formatViewTouchedNiceGrey:v];
}else{
[tappedViewArray removeObject:v];
[super formatViewBorder:v];
}
if (currentIndex == oldIndex) {
isTapped = !isTapped;
}
}
Actual Behavior: After Tapping the First UIView it selects fine and changes, a second tap will change it back, however after successive taps it stays selected. Also, if you select a UIView and go to another view - you have to double tap the successive views.
I would like to just tap once to turn off or on any of the UIViews in the scrollview.
UPDATE: Well, after some Hand writing and other vain attempts at trying to focus on this issue ---- I have solved it this way and it BEHAVES properly!
here is my solution:
- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
isTapped = !isTapped;
UIView *v = gestureRecognizer.view;
NSInteger currentIndex = [studentCellArray indexOfObjectIdenticalTo:v];
if (((isTapped && currentIndex != oldIndex) || (!isTapped && currentIndex != oldIndex)) && [tappedViewArray indexOfObject:v] == NSNotFound) {
oldIndex = currentIndex;
[tappedViewArray addObject:v];
[super formatCornerRadiusWithGreyBackgrnd:v];
} else {
[super formatViewBorder:v];
[tappedViewArray removeObject:v];
}
}
So I hope this helps someone with this issue.
The key was to check for the isTapped and indexes being not equal AND the view object NOT being in the array I was assembling to indicate items touched/Tapped....

Respond to mouse events in text field in view-based table view

I have text fields inside a custom view inside an NSOutlineView. Editing one of these cells requires a single click, a pause, and another single click. The first single click selects the table view row, and the second single click draws the cursor in the field. Double-clicking the cell, which lets you edit in a cell-based table view, only selects the row.
The behavior I want: one click to change the selection and edit.
What do I need to override to obtain this behavior?
I've read some other posts:
The NSTextField flyweight pattern wouldn't seem to apply to view-based table views, where the cell views are all instantiated from nibs.
I tried subclassing NSTextField like this solution describes, but my overridden mouseDown method is not called. Overridden awakeFromNib and viewWillDraw (mentioned in this post) are called. Of course mouseDown is called if I put the text field somewhere outside a table view.
By comparison, a NSSegmentedControl in my cell view changes its value without first selecting the row.
Here's the working solution adapted from the accepted response:
In outline view subclass:
-(void)mouseDown:(NSEvent *)theEvent {
[super mouseDown:theEvent];
// Forward the click to the row's cell view
NSPoint selfPoint = [self convertPoint:theEvent.locationInWindow fromView:nil];
NSInteger row = [self rowAtPoint:selfPoint];
if (row>=0) [(CellViewSubclass *)[self viewAtColumn:0 row:row makeIfNecessary:NO]
mouseDownForTextFields:theEvent];
}
In table cell view subclass:
// Respond to clicks within text fields only, because other clicks will be duplicates of events passed to mouseDown
- (void)mouseDownForTextFields:(NSEvent *)theEvent {
// If shift or command are being held, we're selecting rows, so ignore
if ((NSCommandKeyMask | NSShiftKeyMask) & [theEvent modifierFlags]) return;
NSPoint selfPoint = [self convertPoint:theEvent.locationInWindow fromView:nil];
for (NSView *subview in [self subviews])
if ([subview isKindOfClass:[NSTextField class]])
if (NSPointInRect(selfPoint, [subview frame]))
[[self window] makeFirstResponder:subview];
}
Had the same problem. After much struggle, it magically worked when I selected None as against the default Regular (other option is Source List) for the Highlight option of the table view in IB!
Another option is the solution at https://stackoverflow.com/a/13579469/804616, which appears to be more specific but a little hacky compared to this.
I'll try to return the favor... Subclass NSOutlineView and override -mouseDown: like so:
- (void)mouseDown:(NSEvent *)theEvent {
[super mouseDown:theEvent];
// Only take effect for double clicks; remove to allow for single clicks
if (theEvent.clickCount < 2) {
return;
}
// Get the row on which the user clicked
NSPoint localPoint = [self convertPoint:theEvent.locationInWindow
fromView:nil];
NSInteger row = [self rowAtPoint:localPoint];
// If the user didn't click on a row, we're done
if (row < 0) {
return;
}
// Get the view clicked on
NSTableCellView *view = [self viewAtColumn:0 row:row makeIfNecessary:NO];
// If the field can be edited, pop the editor into edit mode
if (view.textField.isEditable) {
[[view window] makeFirstResponder:view.textField];
}
}
You really want to override validateProposedFirstResponder and allow a particular first responder to be made (or not) depending on your logic. The implementation in NSTableView is (sort of) like this (I'm re-writing it to be pseudo code):
- (BOOL)validateProposedFirstResponder:(NSResponder *)responder forEvent:(NSEvent *)event {
// We want to not do anything for the following conditions:
// 1. We aren't view based (sometimes people have subviews in tables when they aren't view based)
// 2. The responder to valididate is ourselves (we send this up the chain, in case we are in another tableview)
// 3. We don't have a selection highlight style; in that case, we just let things go through, since the user can't appear to select anything anyways.
if (!isViewBased || responder == self || [self selectionHighlightStyle] == NSTableViewSelectionHighlightStyleNone) {
return [super validateProposedFirstResponder:responder forEvent:event];
}
if (![responder isKindOfClass:[NSControl class]]) {
// Let any non-control become first responder whenever it wants
result = YES;
// Exclude NSTableCellView.
if ([responder isKindOfClass:[NSTableCellView class]]) {
result = NO;
}
} else if ([responder isKindOfClass:[NSButton class]]) {
// Let all buttons go through; this would be caught later on in our hit testing, but we also do it here to make it cleaner and easier to read what we want. We want buttons to track at anytime without any restrictions. They are always valid to become the first responder. Text editing isn't.
result = YES;
} else if (event == nil) {
// If we don't have any event, then we will consider it valid only if it is already the first responder
NSResponder *currentResponder = self.window.firstResponder;
if (currentResponder != nil && [currentResponder isKindOfClass:[NSView class]] && [(NSView *)currentResponder isDescendantOf:(NSView *)responder]) {
result = YES;
}
} else {
if ([event type] == NSEventTypeLeftMouseDown || [event type] == NSEventTypeRightMouseDown) {
// If it was a double click, and we have a double action, then send that to the table
if ([self doubleAction] != NULL && [event clickCount] > 1) {
[cancel the first responder delay];
}
...
The code here checks to see if the text field
cell had text hit. If it did, it attempts to edit it on a delay.
Editing is simply making that NSTextField the first responder.
...
}
I wrote the following to support the case for when you have a more complex NSTableViewCell with multiple text fields or where the text field doesn't occupy the whole cell. There a trick in here for flipping y values because when you switch between the NSOutlineView or NSTableView and it's NSTableCellViews the coordinate system gets flipped.
- (void)mouseDown:(NSEvent *)theEvent
{
[super mouseDown: theEvent];
NSPoint thePoint = [self.window.contentView convertPoint: theEvent.locationInWindow
toView: self];
NSInteger row = [self rowAtPoint: thePoint];
if (row != -1) {
NSView *view = [self viewAtColumn: 0
row: row
makeIfNecessary: NO];
thePoint = [view convertPoint: thePoint
fromView: self];
if ([view isFlipped] != [self isFlipped])
thePoint.y = RectGetHeight(view.bounds) - thePoint.y;
view = [view hitTest: thePoint];
if ([view isKindOfClass: [NSTextField class]]) {
NSTextField *textField = (NSTextField *)view;
if (textField.isEnabled && textField.window.firstResponder != textField)
dispatch_async(dispatch_get_main_queue(), ^{
[textField selectText: nil];
});
}
}
}
Just want to point out that if all that you want is editing only (i.e. in a table without selection), overriding -hitTest: seems to be simpler and a more Cocoa-like:
- (NSView *)hitTest:(NSPoint)aPoint
{
NSInteger column = [self columnAtPoint: aPoint];
NSInteger row = [self rowAtPoint: aPoint];
// Give cell view a chance to override table hit testing
if (row != -1 && column != -1) {
NSView *cell = [self viewAtColumn:column row:row makeIfNecessary:NO];
// Use cell frame, since convertPoint: doesn't always seem to work.
NSRect frame = [self frameOfCellAtColumn:column row:row];
NSView *hit = [cell hitTest: NSMakePoint(aPoint.x + frame.origin.x, aPoint.y + frame.origin.y)];
if (hit)
return hit;
}
// Default implementation
return [super hitTest: aPoint];
}
Here is a swift 4.2 version of #Dov answer:
override func mouseDown(with event: NSEvent) {
super.mouseDown(with: event)
if (event.clickCount < 2) {
return;
}
// Get the row on which the user clicked
let localPoint = self.convert(event.locationInWindow, from: nil)
let row = self.row(at: localPoint)
// If the user didn't click on a row, we're done
if (row < 0) {
return
}
DispatchQueue.main.async {[weak self] in
guard let self = self else {return}
// Get the view clicked on
if let clickedCell = self.view(atColumn: 0, row: row, makeIfNecessary: false) as? YourOutlineViewCellClass{
let pointInCell = clickedCell.convert(localPoint, from: self)
if (clickedCell.txtField.isEditable && clickedCell.txtField.hitTest(pointInCell) != nil){
clickedCell.window?.makeFirstResponder(clickedCell.txtField)
}
}
}
}

IPad - how to only type 0~9 on textfield?

Hello
I know ipad keyboard doesn't like iphone can set "UIKeyboardTypeNumberPad"!!
But if I wanna it only can type and show number 0 to 9 on textfield.
How to compare what user key in on textfield are numbers or not ??
Thank in advance.
Mini
instead of comparing a figure after it is displayed, do it in the shouldChangeCharactersInRange
be sure to declare the delegate UITextFieldDelegate, and something i always forget, make sure the delegate of the textField itself is pointing at the class that has the code in it.
//---------------------------------------------------------------------------
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if ([string length] == 0 && range.length > 0)
{
textField.text = [textField.text stringByReplacingCharactersInRange:range withString:string];
return NO;
}
NSCharacterSet *nonNumberSet = [[NSCharacterSet characterSetWithCharactersInString:#"0123456789"] invertedSet];
if ([string stringByTrimmingCharactersInSet:nonNumberSet].length > 0)return YES;
return NO;
}
Take a look at this thread. It solved my similar problem.
How about How to dismiss keyboard for UITextView with return key??
The idea is you check every time the user hits a key, and if it is a number let it through. Otherwise ignore it.
Make your Controller supports the UITextViewDelegate protocol and implement the textView:shouldChangeTextInRange:replacementText: method.
(BOOL) textField: (UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString: (NSString *)string {
NSNumberFormatter * nf = [[NSNumberFormatter alloc] init];
[nf setNumberStyle:NSNumberFormatterNoStyle];
NSString * newString = [NSString stringWithFormat:#"%#%#",textField.text,string];
NSNumber * number = [nf numberFromString:newString];
if (number) {
return YES;
} else
return NO;
}

NSManagedObjectContext save causes NSTextField to lose focus

This is a really strange problem I'm seeing in my app. I have an NSTextField bound to an attribute of an NSManagedObject, but whenever the object is saved the textfield loses focus. I'm continuously updating the value of the binding, so this is far from ideal.
Has anyone seen anything like this before, and (hopefully) found a solution?
I encountered the issue recently and fixed it by changing the way the NSTextField was bound to the NSManagedObject attribute. Instead of binding the value of the text field to the selection.[attribute] key path of the NSArrayController, I bound the arrayController.selection.[attribute] keyPath of the view controller that had a proper outlet pointing to the controller.
For some reason, the NSTextField doesn't loose focus when the NSManagedObjectContext is saved if bound this way.
I want to share my solution. It will work for all fields without modification.
I have optimized it for this posting and removed some error checking, logging and thread safety.
- (BOOL)saveChanges:(NSError **)outError {
BOOL result = YES;
#try {
NSError *error = nil;
if ([self hasChanges]) {
// Get field editor
NSResponder *responder = [[NSApp keyWindow] firstResponder];
NSText *editor = [[NSApp keyWindow] fieldEditor: NO forObject: nil];
id editingObject = [editor delegate];
BOOL isEditing = (responder == editor);
NSRange range;
NSInteger editedRow, editedColumn;
// End editing to commit the last changes
if (isEditing) {
// Special case for tables
if ([editingObject isKindOfClass: [NSTableView class]]) {
editedRow = [editingObject editedRow];
editedColumn = [editingObject editedColumn];
}
range = [editor selectedRange];
[[NSApp keyWindow] endEditingFor: nil];
}
// The actual save operation
if (![self save: &error]) {
if (outError != nil)
*outError = error;
result = NO;
} else {
result = YES;
}
// Now restore the field editor, if any.
if (isEditing) {
[[NSApp keyWindow] makeFirstResponder: editingObject];
if ([editingObject isKindOfClass: [NSTableView class]])
[editingObject editColumn: editedColumn row: editedRow withEvent: nil select: NO];
[editor setSelectedRange: range];
}
}
} #catch (id exception) {
result = NO;
}
return result;
}
OK, so thanks to Martin for pointing out that I should read the docs a little more closely. This is expected behaviour, and here's what I did to get around it (use your judgement as to whether this is appropriate for you):
I save my context once every 3 seconds, checking at the start if the context has any changes before I bother executing the actual save: method on my NSManagedObjectContext. I added a simple incrementing/decrementing NSUInteger (_saveDisabler) to my Core Data controller class that is modified via the following methods:
- (void)enableSaves {
if (_saveDisabler > 0) {
_saveDisabler -= 1;
}
}
- (void)disableSaves {
_saveDisabler += 1;
}
Then all I do in my custom saveContext method is do a simple check at the top:
if (([moc hasChanges] == NO) || (_saveDisabler > 0)) {
return YES;
}
This prevents the save from occurring, and means that the focus is not stolen from any of my custom textfield subclasses. For completeness, I also subclassed NSTextField and enable/disable saves in my Core Data controller from the following methods:
- (void)textDidBeginEditing:(NSNotification *)notification;
- (void)textDidEndEditing:(NSNotification *)notification;
It might be a little messy, but it works for me. I'm keen to hear of cleaner/less convoluted methods if anyone has done this successfully in another way.

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