I have a UIScrollView (managed by a view controller) which I am using both full screen and as a subview. The full screen version works fine - the subview does not.
The subview is positioned so that it takes up about the bottom half of the screen, with a small - 20 pixels or so - margin at the bottom.
Initially it displays in the correct position but overwrites the bottom margin - even though the scrollview's frame is set to leave the margin.
When I scroll the view up by dragging it, the whole view moves upwards and obscures the top of the window. The frame stops moving when it hits the navigation bar at the top and starts scrolling like a normal scrollview. If I scroll it enough it eventually reveals the margin at the bottom of the screen.
I am at a loss to know what to do - I've tried every spring combination I can think of. I'm now looking at subview clipping.
Images below. The first shows the scrollview on initial page load, positioned correctly aside from lower margin overwrite. The scroll view has a white background.
The second image shows it scrolled up toward the top:
The third image shows it scrolled all the way up to the top - note that the lower margin has become visible.
I'm not 100% sure on this one, but worthy the shot: my guess is you're likely not setting the Bounds property correctly on your table.
To solve this issue, the easiest way would be to set myscrollview.clipsToBounds = true.
Something is definitely wrong here. I think what happens is that you are adding the same instance of scrollview as a subview on itself. So basically what you are left with, is one instance alone. Anything you add to the "subview", is basically added on the superview, since it is the same object.
For example, this is what I think you are doing in the view controller:
//...
private UIScrollView myScrollView;
public override void ViewDidLoad()
{
this.myScrollView = new UIScrollView();
this.View = this.myScrollView;
this.View.AddSubview(this.mySrcollView); // same instance
this.myScrollView.AddSubview(aUIButton); // "aUIButton" will be added in View also, since it is the same object
}
If this is the case, it is wrong. I suggest not changing the controller's view at all. If you want to have a controller that has a fullscreen UIScrollView, just create it and add it as a subview, making sure the AutoSizesSubviews property to true.
That's my understanding at least.
Related
I'm implementing a login screen. It has a centred Column containing a TextField for entering an email address and a number of buttons for social sign-in. When a button is pressed, the Column is rebuilt with a CircularProgressIndicator (spinner) added at the bottom. I've wrapped the spinner in a custom widget that manages a ScaleTransition animation. That works OK, but the Column grows and shifts up to accommodate the final full size of the spinner immediately instead of moving smoothly with the animation.
I also wrapped the Column in an AnimatedSize widget using the same curve and duration as the ScaleTransition, but it hasn't helped. The root of the tree is a Consumer of the state that triggers the addition of the spinner so the animations should both be starting together. Maybe the the spinner needs to be permanent for this to work, but it doesn't seem desirable because its API doesn't provide a way to pause the animation. It would presumably constantly use some power to animate itself even when it isn't visible. I'm fussy about that sort of thing.
It looks like I might have to use an AnimatedList, but it doesn't seem semantically correct because the contents aren't really a list. So is there a more generic way to animate the size (and position) of parent widgets like Column and Center to track an animated size change of their children?
I have a Vaadin 8 application with several views.
public class ViewName extends Panel implements View {
There is a VerticalLayout as main layout in the panel.
public ViewName() {
setSizeFull();
VerticalLayout mainLayout = new VerticalLayout();
setContent(mainLayout);
Then I have many different layouts (HorizontalLayout, GridLayout) or Components such as Label being added as components to the mainLayout. For the HorizontalLayouts I often do the following to use the full width of the screen:
hLayout.setWidth("100%");
I have a lot of icons, grids etc. Everything is OK as long as I don't resize the window.
When I resize the window to a small size I get a mess (icons, text etc. on top of each other) and no horizontal scrollbar. (However, the grids get horizontal scrollbars.) I have tried many things to fix this. If I add
mainLayout.setSizeFull();
or
mainLayout.setWidth("100%");
I have a mess on the big screen already. I also tried the CSS for the mainLayout as described here. I get several scrollbars but none for the window itself!
The only component that resizes correctly is a Label added to the mainLayout, e.g.:
Label title = new Label("Some text",ContentMode.HTML);
title.setWidth(100, Unit.PERCENTAGE);
mainLayout.addComponent(title);
mainLayout.setComponentAlignment(title, Alignment.MIDDLE_CENTER);
I also noticed that anything in a GridLayout seems to stay in place after resizing but is not vissible since I have no scrollbar. However, icons in a HorizontalLayout get on top of each other.
What is wrong? Please, I need a general instruction on which layout I should use as main layout for my view panel, how to size the components and how to get ONE horizontal scrollbar for the main window if necessary.
The problem is that you are setting the width of your mainLayout to the width of your view. This means, that your mainLayouts width will never be bigger than your views width. So no scroll bar will appear.
According to the information you posted, changing your mainLayouts width to undefined should fix the problem.
mainLayout.setWidth("-1px");
I have a ScrollPane in my scene and would like to add a series of Nodes to it. The exact amount must be dynamic. I've been testing the concept with Label nodes and can successfully add as many Labels as I want to the content of the ScrollPane (currently a VBox).
My problem is figuring out how to allow the user to scroll normally through the ScrollPane full of Nodes. The content matches pace with the scrollbar; that is, when I scroll down, the content moves down. I scroll up, the content scrolls up. So if I have 10 Labels, only five of which are currently visible, the instinctive action to see the other five would be to scroll down. Unfortunately, this just moves the entire content down, exposing empty space up top and hiding more of the Labels.
I can post some sample code if that helps, but the gist of my plan of attack is this:
ScrollPane sp = new ScrollPane();
VBox content = new VBox();
sp.setContent(content);
for (int i = 0; i < 10; i++)
{
Label label = new Label("Label " + i);
content.setPrefHeight(content.getPrefHeight() + label.getPrefHeight());
content.getChildren().add(label);
}
Because I use a VBox, the Labels are stacked (in the Y axis) atop one another, which is what I want. As more Labels are added, the ScrollBar needs to reflect the increased size of the VBox.
I've tried a few approaches to get this to work, including ScrollPane.setVmax() method, which is ok, but I still have the issue of the scroll direction moving the content in the wrong direction. I've also tried an EventHandler and EventFilter to modify values accordingly, still without solving the problem of scrolls not moving the content in the right direction.
The answer seems so simple, yet the it continues to evade me, even after many long hours messing around with the code.
EDIT:
jewelsea's suggestion of using a ListView solved my problem. However, I remain curious as to why using a ScrollPane did not fare so well. Additionally, I've run into odd behavior with the ListView implementation: I use a button to manually add a new Label to the view. Every now and then, the view will freeze up after adding a new Label. It locks up for a few seconds before either updating the scroll position or displaying the newly added Label. I don't know if this is because there are about 20 or so Label instances being managed by the view or if something more insidious is at play.
In regards to the scrollpane issues, I know what you're looking to do is possible because I'm doing something very similar. Based on the code snippet you gave above I would suggest trying few things...
Give the ScrollPane a preferred height and width to follow.
Don't give the content VBox any height sizing preference as it will grow with its contents. There should be no need to update its height after adding content either.
Use the VBox's setAlignment method to align its contents either TOP_LEFT, TOP_CENTER, or TOP_RIGHT.
Be cautious when using the getPrefHeight() method because if you haven't used setPrefHeight() beforehand I believe it will return -1.
Hope this helps you out!
I want to hold a section label stable at the top of a ScrollViewer in a windows store app, while that section has not scrolled off. For example, the windows weather app does this with the section labels in the top left as you scroll to the right.
Currently the control I want to hold stable is nested inside a ScrollViewer control. I have an intermediate solution that holds it mostly steady by updating the control's render offset in response to the ViewChanged event. However, there's still some very obvious stuttering as I scroll. I've also considered "pretending" the control is in the scroll viewer, when it is actually outside of it, but this would break a lot of encapsulation.
How do I hold a section label perfectly still as the control it is logically inside of is scrolled over?
If you put the ScrollViewer and your Label into a Grid you can keep the label in the same position:
<Grid>
<Label/>
<ScrollViewer>...</ScrollViewer>
</Grid>
I have a view with a UITabBar and the navigation bar is initially hidden. When I press the next tab I want the nav bar to be shown, but when I do this using setNavigationBarHidden: the view gets resized, and the tabbar is pushed out of the screen. How do I setup the views to where they won't get resized? Or get resized properly?
You will have to check your autoresizingMasks. You can adjust them programmatically or via IB. Autosizing is available in the Size Inspector on the right.
You will mostly have to change the tab bar's mask to fix it to bottom and left. Rest of the subviews will have to be handled as needed.
[self.navigationController setNavigationBarHidden:NO animated:NO];
or
after that
set urview frame to exactly for 44reduce(which is navingation bar height) from height.