I currently have a textview with a paddingBottom of 20dp.
I want to reduce this padding if the text within the textView is long enough to otherwise get cut off at the bottom.
Here's a diagram illustrating the behavior I want:
However, I'm not sure where to call setPadding().
Can someone recommend me an approach for getting this behavior of a dynamic bottom padding?
I ended up creating a custom Layout that contained my textView, and overrode its onMeasure() method. The custom layout was set with height='wrap_content'.
The system passes in the available height to this layout's onMeasure() method. So here, I measured my child textView's height with
textView.onMeasure()
int preferredHeight = textView.getMeasuredHeight()
If its preferred height was larger than what my custom view had available to it (minus the bottom padding), I removed the bottom padding with setPadding(). Otherwise, I added the padding.
Related
I'm struggling with getting LinearLayout to behave like I want it. Unfortunately, both dimension modes MATCH_PARENT and WRAP_CONTENT don't seem to fit for my purposes.
Here's why: I want the child that is added to the LinearLayout to be completely visible. Nothing should be cut off. So normally, I should use WRAP_CONTENT to achieve this behaviour.
But, if there's more space in the LinearLayout than the child really needs, I also want it to fill that space. This is of course what MATCH_PARENT is for.
However, I can't use MATCH_PARENT because in case there is less space in the LinearLayout than my child needs, using MATCH_PARENT will cut off the child which I don't want.
So this leaves me somewhat puzzled as to how I can achieve what I want: How can I allow a child to fill additional space in the LinearLayout (if available) while at the same time forcing the LinearLayout to be at least as big as the child needs in order to be completely visible?
Put your child view inside a ScrollView with width MATCH_PARENT, height MATCH_PARENTand set both the child's dimensions MATCH_PARENT
Instead of using MATCH_PARENT for your child, use WRAP_CONTENT and set your child's weight to 1,So it will take all the empty space in your LinearLayout. Suppose your LinearLayout's height is 128dp, and your child 's height is 56dp, your child will be 128dp . If you set WRAP_CONTENT on your LinearLayout, it will be 56dp, and it child will still take all the place it needs.
If you want your LinearLayout to have a minimum width or height, and not match_parent, you can do setMinimumWidth() or setMinimumHeight() in your xml layout or in your code programmatycally depending your childs default height and width.
In framelayout, if I want to put a view in the position that starts from 1/2 of the screen width. How can I do it? Thanks.
You can accomplish that in multiple ways. It only depends if you really need to stick with the FrameLayout.
Two easiest would be those:
FrameLayout - you would need to know whats the width of the layout (so if your layout is wrap_content it might get tricky). Set your view's gravity to left, and set its margin_left to half of the layout's width.
LinearLayout - either put it inside your FrameLayout (not very good practice), or (if you can) swap it with your FrameLayout. Set it's orientation to horizontal, add dummy view with width = 0dp, weight = 1. Then add your view with the same values for width and weight.
I have a custom View I'm making which has a fixed proportion between width and height. I want the programmer to set the height and I would like the View to set its own width according to a formula based on height.
The View is going to be a child of a RelativeLayout so I can't use the height of the parent element to calculate anything.
How can I accomplish this? I don't know how to do it in the onMeasure hook because the View's width and height are not available at that time.
By the way, I am making this view solely programmatically, no XML involved.
use View.setlayoutParams()
There's an example using an adView here.
I have a background image on my app, and I want my listview to be in the form of a window that overlays the background image. Sort of like the the form which has a white filter in this picture:
http://25.media.tumblr.com/ad75c4a9dad9650ed53d754712f4fbb2/tumblr_mgemxiU2W01r2wjwko2_1280.png
I currently have a listview defined in xml with:
android:layout_width="fill_parent"
android:layout_height="fill_parent"
and a semi transparent color as its background. This is great, but it takes up the whole screen, since it fills the parent width and height. What is the best way to make it slightly smaller than the parent's dimensions so that it is say, (fill_parent - some relative value) height and width?
Use margin in a layout to make it smaller relative to the parent layout and other child's
Use a FrameLayout as a parent, then add your ListView and set width and height to wrap_content. Now it should "float" above the other views inside the FrameLayout. You can use padding and margin to set its position.
I'd like to use the center of a View to align it in another View, let's say, a TextView in a RelativeLayout.
I don't want to have it centered inside the RelativeLayout but rather offset from the bottom left corner.
At the moment I align the TextView ParentLeft and ParentBottom and use margins on left and bottom to move it away from those sides.
However, because my TextView is set to wrap_content in width, it "moves" around when the text inside and with it its width changes (since the borders of the TextView are used for the offsets).
I want the center of the TextView to stay on my offsetted position.
Is this possible in the xml, without having to write code that manages the offset or to use another layout?
That's the unwanted behaviour when the text changes: Screen1
The desirable behaviour: Screen2
Note that the center of the TextView stays the same.
There is a simple logic here. If you want to align a view with respect to the parent then for relative layout you can use align_parent wherein in linear use android:layout_gravity. Here in you case make textview as match_parent and set gravity to centre.