How do i position a button in xml. Im using Eclipse with android sdk, i just used margins to put the buttons in positions. But how can i do it through the postion function?
Placing a button on the screen using xml is going to very depending on what you use for your root view group.
There isn't a position function like what you are probably thinking where you would set the X and Y position of the button and for good reason. Because of the hardware fragmentation of android devices it would be difficult to write portable UI if you were relying on hardcoded X and Y coords (regardless of portrait vs landscape).
As an example if i wanted to put a button in the bottom right of the screen and I had a relative layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello"
android:layout_alignParentBottom = "true"
android:layout_alignParentRight = "true"/>
</RelativeLayout>
This will put a button on the button right of the screen regardless of screen pixel density/resolution or even landscape VS portrait
Related
My layout preview doesn't show the action bar only the textviews and buttons I added and when I add a new button or textview, it just goes to the top left corner of the screen even though I tried using Relative and Constraint Layouts. I've tried using "Base.Theme.AppCompat.Light.DarkActionBar" but it doesn't solve it. I've had this issue since I installed android studio on my new PC.Here's a screenshot of my layout preview
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent" android:layout_height="match_parent">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Create Account" />
</RelativeLayout>
It's totally normal that your button is on the top left corner if you don't set its position.
If you add this to your Button:
android:layout_centerInParent="true"
Than your Button will be in the center of the root layout.
You can even use ConstraintLayout for this problem. With the help of constraint layout handles you can easily set the button to the centre position.constraint layout centering button
it can be done easily : join right handle first, then left handle, then top and bottom handle.
also with the help of this, layout will not be distorted on different screens
I am using the Code from JawsWare - Overlay View to create a View that lays above everything.
This works fine, but I failed to adapt the given layout to my needs.
What I want: Two Phases.
First Phase: A button in the upper left corner that is always there above all other apps.
When this button is pressed, we enter the Second Phase:
The button is replaced by two images which are to be horizontally aligned at a certain distance from the top, again floating above everything else.
I have to admit that I dont really understand Android Layouting, but I've tried fiddling with a RelativeLayout and an ImageView but it seems buggy.
Additionally, I encountered a very strange behaviour: Even if the Image is only about 200x200 px in the upper left corner, nearly the whole screen is "blocked" by the View (it receives all TouchEvents, even though there shouldt be anything). It seems that if I position the Layout using Margins to float in the middle of the screen, everything to the left and top of the visible button is also receiving touch events and not letting them pass through to the underlying app (even though there is no visible content).
Any ideas to why this happens and how to circumvent that?
Secondly: How can I achieve the two layouts from earlier?
Edit 1: My Layout. (please keep in mind that I just copied this and then did what I thought was right)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="0dp"
android:onClick="overlayTextClicked"
android:padding="0dp"
android:id="#+id/overlay_layout_id"
>
<ImageView
android:id="#+id/imageview_info"
android:layout_width="200px"
android:layout_height="200px"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:scaleType="fitXY"
android:src="#drawable/picture_010512233437384578"
android:contentDescription=""/>
<TextView
android:id="#+id/textview_info"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:text="info"
android:textColor="#FFF"
android:orientation="vertical"
android:textAppearance="?android:attr/textAppearanceSmall" />
</RelativeLayout>
Afterwards I am trying to set the RelativeLayouts Gravity to TOP | CENTER_VERTICAL with a Top-Margin of 200px.
I believe what's going on here is your TextView is filling out the entire screen.
wrap_content bounds the size of a View with its content. match_parent fills a view to as big as it can get (i.e., whatever size the container is bound to).
So in this case, your RelativeLayout is does not have a max size it's bound to. Your TextView is going to try to get as big as it can get, so it's going to fill the screen. Likewise, the RelativeLayout is going to blow up to that size to wrap around the TextView.
Also, RelativeLayout doesn't really respond to Gravity well. That is used in LinearLayout and FrameLayout containers a lot, but RelativeLayout relational rules like "CENTER_IN_PARENT" are going to override whatever Gravity you set (if you set Gravity.RIGHT and "CENTER_IN_PARENT", then one has to win out I guess).
I'm implementing a simple flip-clock / counter / ticker widget which will consist of several instances of a following "digit" widget:
It's a digit placed on top of a background image. The digit is supposed to animate every second by sliding up and revealing next digit. During the animation both digits should stay "within" the background's boundary.
I'm trying to achieve this behavior by having a TextView with 2 lines - one digit per line - and animating this TextView's position upwards, until the next digit is fully visible. And then I will reset TextViews position and replace both digits at the same time, so that it's impossible to notice. Then I will repeat the process and make it look like the animation never ends.
Here you can see an intermediate state of the animation, when part of zero and part of nine is visible. I "mocked" it in the Graphical Layout editor of Eclipse, by setting the layout_marginTop property to a negative value.
Here's the layout file (the mentioned attribute is normally not there).
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="20dp"
android:layout_height="38dp"
android:background="#drawable/background_countdown_normal_grey"
android:clipChildren="false" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:paddingBottom="5dp"
android:paddingTop="5dp" >
<TextView
android:id="#+id/textview_countdown_digit"
style="#style/TextView.CountdownDigit"
android:layout_marginTop="-12dp"
android:text="0\n9" />
</LinearLayout>
</LinearLayout>
I tried two solutions. By using ViewPropertyAnimator on either translateY or y, I get a smooth animation, but the original clipping of the TextView does not change during animation, so in effect the second digit is never visible. As you can see, I tried clipChildren property, but it doesn't seem to change anything.
My second approach was to use ValueAnimator with a custom Evaluator, which modifies the topMargin of LayoutParams on the TextView. It works, but the animation is very choppy even on high-end devices.
So my question is, how to avoid view clipping during animation and make so in an efficient way? Is there a better approach?
I found an alternative solution in which I use a ScrollView instead. My layout looks like this:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/scrollview_countdown_digit"
android:layout_width="20dp"
android:layout_height="38dp"
android:background="#drawable/background_countdown_normal_grey"
android:paddingBottom="5dp"
android:paddingTop="5dp"
android:scrollbars="none" >
<TextView
android:id="#+id/textview_countdown_digit1"
style="#style/TextView.CountdownDigit"
android:text="0\n9" />
</ScrollView>
I animate using ObjectAnimator by scrollY property. Works well so far.
I also tried having 2 TextViews intsead of one (in my initial layout), but it did not change the fact of clipping.
After much research on both SO and google, I haven't seen any one with exactly the same problem I am experiencing, so here it is:
I recently redid the entire UI on an android app. For the most part, I made only cosmetic changes to each of the screens. They appear in the UI editor of eclipse perfectly as expected. However, directly after doing this, two of the screens stopped being laid out correctly on both all tested devices and the emulator.
Now, the big problem one these two screens was that the root level LinearLayout didn't appear to be actually honoring the fill_parent for either layout_height or layout_width. it looks like it's being measured as if it were set to wrap_content instead. It only takes up about 70% of the screen - which is just enough to wrap the individual elements inside the root LinearLayout. I would post an image, but as a new user, I am not allowed to.
The layout isn't stretching to fill the screen. Here's the code for layout, except that there are a few more in the LinearLayouts containing a TextView and an EditText.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF000000"
android:orientation="vertical" >
<TextView
style="#style/sans.white.16.bold"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="4dp"
android:text="#string/edit_account" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<com.teamunify.ondeck.widget.TUTextView
style="#style/sans.white.14"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:text="#string/first_name" />
<com.teamunify.ondeck.widget.TUEditText
android:id="#+id/acc_editor_first"
android:layout_width="fill_parent"
android:layout_height="40dp"
android:selectAllOnFocus="true"
android:singleLine="true" />
</LinearLayout>
I think the root LinearLayout should be filling both height and width. I've used this same layout many MANY times in our app without problems. (A quick count revealed that I used 76 LinearLayouts in our app, and all but two of them are working.)
At first, I suspected that perhaps our custom classes measure was wrecking things, so I changed the layout to use all plain EditTexts, but there was no change. I double checked the activity, but it isn't doing anything except to load this xml. So, in desperation, I redid the layout like so:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF000000"
android:orientation="vertical" >
<TextView
style="#style/sans.white.16.bold"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center|top"
android:paddingTop="4dp"
android:text="#string/edit_account" />
</LinearLayout>
After that, The words Edit Account appear with a black background mashed into the upper left corner. Clearly, the LinearLayout isn't filling the parent.
Long story short, I am asking how to fix this so that the LinearLayout fills the screen as expected.
I am at a complete loss as to why this is happening, and I am certainly hoping that someone on SO has an idea. This has got me pulling my hair out!
Try setting fixed width and height for the root layout.
Then only you will be able to debug who is driving length and width. It is very much possible that parent activity or background activity is setting dimensions. Once you identify the root cause you can go back to original settings.
As of now from your code snippet given here, nothing wrong here
If you use a custom activity as a container to other activities for some reason (In our case, we were recreating the look of our iOS app, and needed a custom menu to show up along the button side of the screen) the window manager seems to get a bit confused with what the actual height and width of the nested activities should be. A call to fillparent or matchparent ends up wrapping the content instead.
We ended up changing the behavior of several methods in our container activity class to make this work.
My current layout displays activity that is not full screen (that's OK).
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="100dip"
android:layout_height="200dip" >
<TextView android:layout_height="wrap_content" android:id="#+id/textView1"
android:layout_width="fill_parent" android:text="#string/hello"></TextView>
I also added android:theme="#android:style/Theme.Translucent" to manifest for my activity.
My 200x100dip activity now shows in the upper left corner. How can i specify position of my linear layout (or my activity)?
You can use either FrameLayout or RelativeLayout as outer most layout for this. Ant then use absolute position in dp or android:layout_centerInParent or similar.
I believe your Activity´s outmost layout element (LinearLayout) will be placed in a FrameLayout that is the parent given from Android. I suggest you let your outmost layout match_parent/fill_parent in layout_height and _width and then center the content inside it with gravity="center" on your outmost layout. By letting the outmost layout being transparent and not catch click element it will appear as layout in the middle where elements behind is visible. If Im correct guessing that's what you want to achieve here.
put that layout in another absolute layout in which you use android:layout_width="fill_parent" and android:layout_height="fill_parent" the other thing you can do is to use this: http://www.droiddraw.org/
you can move your elements around manually with that and it will give you the XML code that is used to do that. I found it very useful in laying out XML in android.