¿Cómo puedo utilizar el zoom de pellizco (UIPinchGestureRecognizer) para cambiar el ancho de una UITextView?

Question

Puedo obtener el controlador UIPinchGestureRecognizer para trabajar con el escalado de un objeto, pero no quiero escalar Quiero cambiar el tamaño. Por ejemplo, tengo un UITextView y le he adjuntado un gesto UIPinchGestureRecognizer y si el usuario pellizca quiero cambiar el ancho de la vista de texto para que coincida con el pellizco. No quiero escalarlo para que el UITextView sea más grande (zoom).

Answer 1

Creo que lo que quiere hacer es simplemente multiplicando el ancho del marco de su Textview con la escala del reconocedor gesto:

CGFloat scale = gestureRecognizer.scale; 
CGRect newFrame = textView.frame; 
newFrame.size = CGSizeMake(scale*newFrame.size.width, newFrame.size.height); 
textView.frame = newFrame; 

O no es esto lo que quiere decir?

Answer 2

Estoy haciendo exactamente lo mismo. Actualizaré esta publicación si encuentro cómo hacerlo.

Prueba de esto, que funcione para mí (por UIView):

- (IBAction)handlePinchGesture:(UIGestureRecognizer *)sender { 
    static CGRect initialBounds; 

    UIView *_view = sender.view; 

    if (sender.state == UIGestureRecognizerStateBegan) 
    { 
     initialBounds = _view.bounds; 
    } 
    CGFloat factor = [(UIPinchGestureRecognizer *)sender scale]; 

    CGAffineTransform zt = CGAffineTransformScale(CGAffineTransformIdentity, factor, factor); 
    _view.bounds = CGRectApplyAffineTransform(initialBounds, zt); 
    return; 
} 

Answer 3

Tengo cuatro rutinas que tienen que ver con el pinzamiento de un campo de texto. El reconocedor de gestos es la rutina central. Ve si los campos de texto seleccionados van a ser pellizcados fuera de la pantalla, no quiero eso. Si no lo son, entonces le digo que se pellizque con la escala del gesto. Si hay varios seleccionados, envío una notificación para aquellos que no se desentonarán de la pantalla para pellizcarse.

//-------------------------------------------------------------------------------------------------------- 
    // pinchElement 
    // Description: Called to di the element scale, in our case, we are adjusting the length. 
    // 
    //-------------------------------------------------------------------------------------------------------- 

- (void)pinchElement:(CGFloat)scale { 

     //Grab how big we are now 
    CGRect textFieldBounds = textField.bounds; 

     //Multiple the Scale of the Pinch by the Width to get our new width. 
    CGFloat newWidth = textFieldBounds.size.width * scale; 

    CGFloat widthChange = newWidth - textFieldBounds.size.width; 
    CGRect newBounds = CGRectMake(0, 0, newWidth, textFieldBounds.size.height); 

    [textField setBounds: newBounds]; 
    [textField setCenter: CGPointMake(textField.center.x + widthChange/2, textField.center.y)] ; 
    [self contentSizeChanged]; 

} 
    //-------------------------------------------------------------------------------------------------------- 
    // pinchOffScreen 
    // Description: Called to see if the Pinch Gesture will cause element to go off screen Gesture 
    // 
    //-------------------------------------------------------------------------------------------------------- 

- (BOOL)pinchOffScreen:(CGFloat)scale { 

     //Grab how big we are now 
    CGRect textFieldBounds = textField.bounds; 

     //Multiple the Scale of the Pinch by the Width to get our new width. 
    CGFloat newWidth = textFieldBounds.size.width * scale; 


     //Figure out our Change in Width so we can calculate our new Zen Center 
    CGRect newElementBounds = CGRectMake(0, 0, newWidth+ kElementFrameOffset*2 + kElementContentFrameOffset*2, textFieldBounds.size.height + kElementFrameOffset*2 + kElementContentFrameOffset*2); 


     //We want to be sure that we dont size beyond our bounds, find our Parent Origin. 

    CGRect elementBoundsInSuperView = [self convertRect:newElementBounds toView:[self superview]]; 

    CGFloat xPosition = CGRectGetMidX(elementBoundsInSuperView); 
    CGFloat yPosition = CGRectGetMidY(elementBoundsInSuperView); 


    BOOL offScreen = [self calcOffEditorFromXposition:xPosition yPosition:yPosition fromBoundsInSuperView:elementBoundsInSuperView]; 
    return offScreen; 

} 

    //-------------------------------------------------------------------------------------------------------- 
    // handlePinchGesture 
    // Description: Called when we get a Pinch Gesture 
    //     We want to override the default scaling and set the width.    
    // 
    //-------------------------------------------------------------------------------------------------------- 

- (void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer { 
    if (IoUIDebug & IoUIDebugSelectorNames) { 
     NSLog(@"%@ - %@", INTERFACENAME, NSStringFromSelector(_cmd)); 
    } 

     // UIView *element = [gestureRecognizer view]; 

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) { 

      //We are resizing, Select ourself 



      [self selectSelf]; 
    } 

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) { 

     NSSet *selectedElements = [[(IoScreenEditorViewController *)UIAppDelegate.ioMainViewController.currentViewController editorContentViewController] selectedElements]; 

     BOOL aSelectedElementOffscreen = FALSE; 
     for (IoUIScreenElement* element in selectedElements) { 
      if ([element pinchOffScreen:[gestureRecognizer scale]]) { 
       aSelectedElementOffscreen = TRUE; 
       break; 
      } 
     } 
     if (!aSelectedElementOffscreen) { 

      [self pinchElement:[gestureRecognizer scale]]; 

       // Let others know they are moving if they are selected 
       // Setup our data for the Notification 
      NSMutableDictionary *theUserInfo = [[[NSMutableDictionary alloc] initWithCapacity:1] autorelease]; 
      [theUserInfo setObject:self forKey:@"ElementWithGesture"]; 


      NSNumber * scaleAsNumber = [[NSNumber alloc] initWithFloat:[gestureRecognizer scale]]; 
      [theUserInfo setValue:scaleAsNumber forKey:@"GestureScale"]; 
      [theUserInfo setObject:gestureRecognizer forKey:@"TheGestureRecognizer"]; 
      [scaleAsNumber release]; 
       // Post the Group Rotation Notification. 
      [[NSNotificationCenter defaultCenter] postNotificationName:kNCSEGroupPinchGesture 
                   object:nil 
                   userInfo:theUserInfo];  
     } 
     [gestureRecognizer setScale:1]; 
    } 
    if ([gestureRecognizer state] == UIGestureRecognizerStateEnded) { 


    } 


} 



    //-------------------------------------------------------------------------------------------------------- 
    //  groupHandlePinchGesture: 
    // Description: For a groupPinch Notification. Move it! within bounds of course 
    // 
    //-------------------------------------------------------------------------------------------------------- 

- (void) groupHandlePinchGesture:(NSNotification*)notification{ 

    if (IoUIDebug & IoUIDebugSelectorNames) { 
     NSLog(@"%@ - %@", INTERFACENAME, NSStringFromSelector(_cmd)); 
    } 

    IoUIScreenElement *element = (IoUIScreenElement *) [[notification userInfo] objectForKey:@"ElementWithGesture"]; 
     //UIRotationGestureRecognizer *gestureRecognizer = (UIRotationGestureRecognizer *) [[notification userInfo] objectForKey:@"TheGestureRecognizer"]; 

    NSNumber *scaleAsNumber = [[notification userInfo] valueForKey:@"GestureScale"]; 
    CGFloat scale = [scaleAsNumber floatValue]; 


    if (IOFNOTEQUAL(self, element) & [self isSelected]){ 
     [self pinchElement: scale]; 
    } 

} 

Answer 4

Usted tiene que usar en Swift:

func pinchgsterAction(gesture:UIPinchGestureRecognizer){ 
    if (gesture.state == UIGestureRecognizerState.Changed) { 
     let scale:CGFloat = gesture.scale 
     gesture.view.transform = CGAffineTransformScale(gesture.view.transform, scale, scale) 

    } 
    }