How to apply animation on LayoutParams - android

I'm wondering if there is a way to apply animation on LayoutParams. Here is the story.
Say I have the following layout, a TextView on the left top corner of a RelativeLayout.
<RelativeLayout ...>
<TextView
android:alignParentStart="true"
android:alignParentTop="true"/>
...
<RelativeLayout />
Then I want to move the TextView to center of the RelativeLayout using animation. After the animation, the layout will become
<RelativeLayout ...>
<TextView
android:centerInParent="true"/>
...
<RelativeLayout />
Just wondering if there is a way to do it using Animator? Thanks.

One thing you can do is position the TexView always at the center of his parent using android:centerInParent="true", and using ValueAnimator or ObjectAnimator to animate the width and height of his parent.
Obviously it would be better if you can somehow calculate the width of the screen but for that i guess is enough to extend the layout parent class (RelativeLayout) and override his onMeasure or onLayout method.

Related

Why LinearLayout's margin is being ignored if used as ListView row view

I was wondering, if I merely provide a single layer of LinearLayout as ListView's row view, its margin will be ignored.
Margin will be ignored if used of ListView's row view
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="5dp"
However, if I provide double layer of LinearLayout, with first layer acted as "dummy" layer, its margin will not be ignored.
We will have margin in ListView's row view
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/buyPortfolioLinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="5dp"
May I know why it happen so?
The fact is that, the margin of LinearLayout (child) asks its parent layout (container) to give child layout a margin of x value.
So if the parent layouts' LayoutParams support the margins then that margin is honored and applied.
ListView uses AbsListView.LayoutParams by default, which doesn't include any margin support, just the height and width, thats why, it simply ignores the params value for margins.
Whereas other layout params like ActionBar.LayoutParams, FrameLayout.LayoutParams, GridLayout.LayoutParams, LinearLayout.LayoutParams and RelativeLayout.LayoutParams are child of ViewGroup.MarginLayoutParams, which honors the child's margin values.
when you use a sigle layout this means this is your window if you apply margin on it then you'll asking for the margin of that amount from your parent view but we don't have parent view so margin won't work.
on second place there is parent view and margin will help for internal view but not for external.
Instead of adding a nested layout, you could use padding like so:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="5dp"

what's different between layout_gravity="top" and android:layout_alignParentTop="true"?

I wanna put image in top of View and a listview bottom of it.
what's best and correct way?
LinearLayout?RelativeLayout?
and with which attribute?
layout_gravity="top"?
layout_alignParentTop="true"?
please give me a snipped code and a brief description about:
what's different between layout_gravity="top" and android:layout_alignParentTop="true"?
I wanna put image in top of View and a listview bottom of it. what's
best and correct way?
If you want to place a ListView below an ImageView positioned at the top of the current view then you could use both layouts, it isn't any real difference.
The layour_gravityis used to place the children relative within its parent bounds(the Relativelayout doesn't have this attribute). For example you could use a LinearLayout with orientation vertical which will stack your two children one on top of the other like you want. Also layout_gravity="top" is ignored for a vertical orientated LinearLayout as it doesn't make sense, so you could remove it from the layout completely:
<LinearLayout android:orientation="vertical">
<!-- the layout_gravity is useless int this case and could be removed-->
<ImageView android:layout_gravity="top"/>
<ListView />
</LinearLayout>
layout_alignParentTop is a placement rule for children of RelativeLayout(only for this type of layout!) which tells them to position aligning the top of the children with the top of the parent RelativeLayout. In this case, to stack the children you would do:
<RelativeLayout>
<!-- you could remove the layout_alignParentTop attribute because by default the Relativelayout will position it's children there -->
<ImageView android:id="#+id/imageId" android:layout_alingParentTop="true" />
<!-- Position this child below the other -->
<ListView android:layout_below="#id/imageId"/>
</RelativeLayout>

Add a Textview to a FrameLayout in a determined position

I'm trying to add a textView to a frameLayout. The TextView has wrap_content properties, so it grows when the text grows. I'm adding it to a FrameLayout with this function:
((FrameLayout) findViewById(R.id.mainLayout)).addView(mEditText);
This is the xml of the frame layout:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mainLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</FrameLayout>
The textView always appears in the top left corner of the screen. I'd like to position it in the middle, or top middle. How can this be done?
I looked over the answers in How can I dynamically set the position of view in Android? and they weren't much help :( Mainly caused crashes..
Try this:
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT, Gravity.CENTER);
((FrameLayout) findViewById(R.id.mainLayout)).addView(mEditText, params);
Change Gravity to suit your need.
BTW, the frame layout should use fill_parent for width and height
Try to gravity or Layout gravity to your Framelayout or the Textview. It makes your Layout to the center of the screen. Use like this,
android:layout_gravity="center"
or
android:gravity="center"
Add android:layout_gravity="center" in your frame layout
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mainLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" >
</FrameLayout>
you can try it by set the gravity of text use it like-
textview.setGravity(Gravity.center);
othervise by xml set gravity to center so it will display you in center and if you'll use centerinparents so it will always apperas at the center of screen.
Set FrameLayout properties android:layout_width and android:layout_height to fill_parent and also set TextView property LayoutGravity . such as Center, Right or Top.
Thanks
Setting the gravity programatically definitely works
Please set the layout_gravity to right in the xml
TextView.setGravity(Gravity.RIGHT);

Android overlay outside/between layout boundaries

I have to add an overlay (ImageView) so that it's a bit shifted to the left of the containing layout's left boundary.
What is the best way to do this?
Tried something simple, like putting the ImageView inside the layout and use negative margin
android:layout_marginLeft="-20dip"
This made this:
(Correction: Text in the image should be 20dip not 20px)
AbsoluteLayout is deprecated. Is there something like z-order? Or what do I do?
Thanks in advance.
Edit: I tried using relative layout instead. Same effect. Here's the xml reduced to a minimum:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:clipChildren="false"
android:paddingLeft="50dip"
>
<ImageView
android:id="#+id/myId"
android:layout_width="60dip"
android:layout_height="60dip"
android:layout_marginLeft="-30dip"
android:clipChildren="false"
android:src="#drawable/pic" />
</RelativeLayout>
Result
Also happens when the containing layout has a background image smaller than the screen instead of padding.
Using RelativeLayout instead of LinearLayout (to allow overlapping) and adding this to the RelativeLayout fixed it:
android:clipToPadding="false"
set "android:clipChildren = false" in xml
Instead of
android:layout_marginLeft="-30dip"
try with
android:paddingLeft="-30dp"
Use a transparent(android:background="#00000000") imageview to the left of linear layout with width = 30dp. And make myId as aligning left in case of relative layout. If you are using linear layout make orientation as horizontal and let the transparent imageview be the first entry in it.

android: how to make a child view overlap the parent?

I need to implement the layout as in the picture. Parent and Sibling are in a vertical LinearLayout. So I need to make a child view to overlap it's parent. Can I do that in android?
If:
sibling is a sibling of parent
parent is a ViewGroup
and you really want child to be a child of parent
then maybe you could consider using android:clipChildren set to false on parent.
I was actually just looking at an example of a FrameLayout that had a TextView overlaid on top of an ImageView. So, there are obviously multiple ways to get it done. Your next question might be which one is best ... to that I have no idea, but here's a guy that might:
http://www.curious-creature.org/2009/03/01/android-layout-tricks-3-optimize-part-1/
Just contain them all within a RelativeLayout, and remember the draw order is top to bottom, so put the top most view on the bottom of the XML definition.
If you use a RelativeLayout you should have no problem achieving this effect. By default it will stack all of its children on top of each other in the top left corner if you don't supply them with android:layout parameters. So it will definitely support overlapping children. You'd just have to figure out what the best way to tell it where the child should go on the screen relative to something else.
There are at least two layouts that can do that. AbsoluteLayout and RelativeLayout. I suggest that you put your views in a RelativeLayout and add them with LayoutParams that specify their offset form the top and left of the parent:
RelativeLayout.LayoutParams rlp;
label = new TextView(ctx);
label.setBackgroundColor(0x00000000);
label.setTextColor(0xFF7ea6cf);
label.setTextSize(13);
label.setGravity(Gravity.LEFT);
label.setText("Examples:\n- Fentanyl\n- Dilaudid 2 mg PO q 4 hours prn moderate pain");
rlp = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT,100);
rlp.topMargin=189;
rlp.leftMargin=30;
rlp.rightMargin=30;
rlParent.addView(label,rlp);
In my case, I have to set android:clipCildren to be false on the parent of parent.
i.e.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:id="#+id/parent1">
<FrameLayout
android:id="#+id/parent2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="64dp"
android:background="#android:color/holo_blue_bright">
<View
android:id="#+id/This_is_the_view_I_want_to_overlap_parent2"
android:layout_width="160dp"
android:layout_height="80dp"
android:layout_gravity="top|start"
android:layout_marginTop="-40dp"
android:background="#000000" />
</FrameLayout>
</FrameLayout>

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