How do I adjust a UIButton relative to its current position? - iphone

I'm trying to work with a scroll view controller that needs to adjust it's contents based on user interaction -- specifically, by adding a 'done' button while the user is working with a UITextView, then removing it when they are done. The problem is making room for the button in question. What I'd like to do is...
control.layer.position.x-=50;
for every single control that is 'below' the one I'm working with. Unfortunately, that doesn't work. As far as I can tell, I'm going to have to do something more like...
control.layer.position=CGPointMake(newX, newY);
This creates a maintainability nightmare; instead of being able to rearrange buttons inside UIBuilder at will, I'm going to have to change their positions in the code as well. Unfortunately, no matter what variant of the first type of code I use, the result doesn't work; I'm informed that I need an lvalue to the left of the assign or that I'm trying to manipulate incompatible types.

It'll be more verbose than the -= solution, but why don't you just calculate newX and newY based on their old values?
e.g.
CGPoint oldPosition = control.layer.position;
control.layer.position = CGPointMake(oldPosition.x - 50, oldPosition.y);

The button comes with a center property, so:
button.center = CGPointMake(button.center.x - 50, button.center.y);
should do the trick

Related

Unity editor - How to stop field from turning blue when its edited

I am making a tool in Unity to build your project for muliple platforms when you press a button.
I started with the preferences window for the tool, and came up with an anoying thing. Whenever I change the enum value of the EnumPopup field, the field turns blue in the editor window. Is there a way to disable this?
See how in the 2nd picture the field is not blue, and in the 3rd picture the field has changed to blue? How do I prevent this from happening?
Thanks in advance!
Difficult to help without having the rest of your code.
This is Unity built-in behaviour. I tried a lot of stuff see here to disable / overwrite the built-in coloring of prefix labels but had no luck so far.
A workarround however might be to instead use an independent EditorGUI.LabelField which will not be affected by the EnumPopup together with the EditorGUIUtility.labelWidth:
var LabelRect = new Rect(
FILEMANAGEMENT_ENUMFIELD_RECT.x,
FILEMANAGEMENT_ENUMFIELD_RECT.y,
// use the current label width
EditorGUIUtility.labelWidth,
FILEMANAGEMENT_ENUMFIELD_RECT.height
);
var EnumRect = new Rect(
FILEMANAGEMENT_ENUMFIELD_RECT.x + EditorGUIUtility.labelWidth,
FILEMANAGEMENT_ENUMFIELD_RECT.y,
FILEMANAGEMENT_ENUMFIELD_RECT.width - EditorGUIUtility.labelWidth,
FILEMANAGEMENT_ENUMFIELD_RECT.height
);
EditorGUI.LabelField(LabelRect, "File relative to");
QuickBuilder.Settings.Relation = (QuickBuilder.Settings.PathRelation)EditorGUI.EnumPopup(EnumRect, QuickBuilder.Settings.Relation);
As you can see the label is not turned blue while the width keeps being flexible
Sidenotes
Instead of setting values via edito scripts directly like
QuickBuilder.Settings.Relation = you should always try and use the proper SerializedProperty. It handles things like Undo/Redo and also marks the according objects and scenes as dirty.
Is there also a special reason why you use EditorGUI instead of EditorGUILayout? In the latter you don't need to setup Rects.
EditorGUILayout.BeginHorizontal();
{
EditorGUILayout.LabelField("File relative to", GUILayout.Width(EditorGUIUtility.labelWidth));
QuickBuilder.Settings.Relation = (QuickBuilder.Settings.PathRelation)EditorGUILayout.EnumPopup(QuickBuilder.Settings.Relation);
}
EditorGUILayout.EndHorizontal();

Can QML drag-and-drop mechanic work without drag item moving?

I have a listview and a rectangle on top of it. The ListView's delegates have DropAreas in them and the rectangle has drag enabled on Y axis with its relevant properties (hotspot, target).
When I move the rectangle up and down on the ListView, the DropAreas of the delegates are registering onEntered signals. Working as intended.
However, I am using SmoothedAnimation to scroll the list up and down when the rectangle is at the most top and bottom coordinates (list.y = 0 and list.height). So the rectangle is not moving, and the DropAreas of the list's delegates are moving under it. In that case, the onEntered is not registered because there is no dragging, the rectangle is completely still and although its hotspot is entering and leaving the DropAreas, there is no interaction.
This is because dragging mechanic is sending events all the time when moving and any DropAreas it comes inside can register the event. In my case there is no dragging and therefore no events.
Question: Can drag events be manually activated? Can I somehow simulate drag?
At first, you should change the drag.target: parent to drag.target: this. In this way instead of dragging the parent item, you drag only the mouseArea. After that, you should grab an image from the item that you want to drag. The code is here:
Rectangle {
id: rec
width: 100
height: 100
Drag.active: dragArea.drag.active
Drag.dragType: Drag.Automatic
Drag.supportedActions: Qt.CopyAction
MouseArea {
id: dragArea
anchors.fill: parent
drag.target: this
onPressed:{
parent.grabToImage(function(result) {
parent.Drag.imageSource = result.url
})
}
}
}
I have managed to induce drag events by manually changing the hotSpot property of the rectangle above the list. QML Drag documentation says:
Changes to hotSpot trigger a new drag move with the updated position.
So I have done this every time Listview contentY changes (vertical scrolling happens)
onContentYChanged:
{
rectangle.Drag.hotSpot.x += 0.0001
rectangle.Drag.hotSpot.x -= 0.0001
}
In hindsight, however, this is a 'hacky' solution. hotSpot property is a QPointF class property (link). This means it can be set using various methods (setX, setY, rx, ry..). For example, this:
rectangle.hotSpot += Qt.point(0,0)
or
rectangle.hotSpot = Qt.point(rectangle.hotSpot.x,rectangle.hotSpot.y)
should work in theory by resetting the hotSpot point when contentY changes, but testing revealed it unfortunately does not trigger a new drag move. (bug or intended, I don't know)
Now some of you that are more into Qt and QML might know more about this and how to properly adress the issue, but the above solution works for me and after testing everything I could imagine to get a cleaner solution, I settled on it.

Why will my label not change location when trying to add additional text field?

So I have a button on my storyboard. When that button is pressed, I want to move a certain label down a little bit and also add a new text field to the screen. Here is the simplified code:
UIView.animateWithDuration(0.5, animations: { () -> Void in
self.addIngredientLabel.center.y += self.addIngredientLabel.bounds.height
}) { (_) -> Void in
let newIngredientTextField = UITextField(frame: CGRectMake(100, 110, 100, 100))
newIngredientTextField.center.y -= 50
newIngredientTextField.placeholder = "place text here"
newIngredientTextField.contentHorizontalAlignment = .Left
self.view.addSubview(newIngredientTextField)
}
The problem though, is that after the animation is completed, the label jumps back to its original location. It is like the animation is being pre-maturely terminated. The textField gets added and the label moves but it does not stay moved.
I have tried adding the text field at the end of the function instead of in a completion block. No kind of reordering seems to be helping.
I feel like I am not understanding something fundamental to animations. If anyone has any advice I would greatly appreciate it.
Since you're using the storyboard, you are most likely also using auto-layout. The positions of your controls are determined in your visual design (storyboard) and will adjust automatically to orientation changes and adapt to various device screen sizes. This is good but the flip size is that you cannot directly change the positions of your control using their x,y coordinates.
Instead, you can change values in the constraints you defined in the storyboard. for example, if you button has a "Top" distancs constraint with a control above it (or the edge of the view), you can change the constraint's "constant" attribute to indirectly change the position of the control.
In order to manipulate the contraints in your code, you can create IBOutlets for them just as you would do with any control.

set the start point of CGRect iPhone

I created a Popup like what in the following link
Popup
and everything are Ok, but if I want to change the size of this popup I go to the file "LeveyPopListView.m" in function
- (void)drawRect:(CGRect)rect
and change the values in this line
CGRect bgRect = CGRectInset(rect, 50, 90);
but if I want to change the value of the start point of this popup, how can I do this?
Thanks in advance.
By the time the system sends the drawRect: message, it is too late to change the position and size of the view.
You need to change the frame of _tableView. It's set on lines 33-36 of LeveyPopListView.m. You didn't say exactly how you want to change it, but you might be able to get the effect you want by changing the definition of POPLISTVIEW_SCREENINSET on line 12.

Computing the bottom of table view content

Could somebody check my thinking here: I'd like to know when a table view is being pulled past the bottom (wish I knew the term for this) ... when the contentInset below the last row is visible and releasing causes a bounce. Here's what I think it is, but I can barely describe it in English, and can't think of a good way to test it....
CGFloat contentBottom = MAX(0, tableView.contentSize.height - tableView.frame.size.height);
BOOL isScrolledToBottom = tableView.contentOffset.y > contentBottom;
It looks right within a few pixels in the debugger, but I feel like I am missing some much simpler way.