Problem building layout programmatically - android

I am building something like a ListView, but I'm rolling my own because I want to do some custom stuff and have more control than using ArrayAdapters.
So I've defined part of my layout in XML, including one LinerLayout inside a ScrollView. My goal is to bind to that Linearlayout in code, then insert additional RelativeLayouts inside the LinearLayout using no XML, just code.
Here is my XML:
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/ListScroll"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:id="#+id/ListHolder"
android:layout_height="400px"
android:background="#323232"
>
<!--Here is where I want the RelativeLayouts to go... -->
</LinearLayout>
</ScrollView>
Then in code, I'm trying to add RelativeLayouts, each 50px in height, to the LinearLayout, the one above that has a height of 400px.
//The parent container - is defined above in XML.
itemContainer = new LinearLayout(context);
itemContainer = (LinearLayout)findViewById(R.id.ListHolder);
Layouts = new ArrayList<RelativeLayout>();
Layouts = LoadWithRelativeLayouts();
for(RelativeLayout listItem: Layouts){
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT, 40);
listItem.setLayoutParams(params);
itemContainer.addView(listItem);
}
Each one of the layouts in the array has a text view in it that says "Test". When I step through the code, there are 10 elements in the array, and all of the textviews are there, so I would expect to see the 400px LinearLayout filled with 10 Relative layouts one after another, each with 50px height (and fill_parent width) reading "Test" - but all I see is one, as if only one got added, or they are all positioned on top of one another.
Getting screenshot now...

When you add something to a layout, you have to use layout params of that kind. So as you're adding to a LinearLayout, you should use LinearLayout.LayoutParams.
Then you'll probably also need to set your LinearLayout orientation to vertical, because right now the items you don't see are all in a row offscreen at the right :)

Try adding android:orientation="vertical" to the LinearLayout holding the RelativeLayouts.

Related

LinearLayout with percent empty space

I am working on linear layout for my simple android application. I wanna make the portion of two views dynamically change based on the size ( I want to have, for a row for left to right, the first 20% is empty, and all the content is inside the rest of 80%) . For this approach, i chosen the weight for different view. I created an nested linear layout for this approach. For example, the layout hierarchy is something like this.
<linearLayout> //parent layout
<linearLayout //child 1 layout
android:layout_weight="1">
//so that this view occupy 20% of the space regardless the width of device. I intensionally wanna keep this view empty.
</linearLayout>
<linearLayout //child 2 layout
android:layout_weight="4">
//so that this view occupy 80% of the space regardless the width of device. and
//inside this view I have whatever view I wanna add on it.
<EditText>
<ImageView>
</linearLayout>
</linearLayout>
With this approach, the Lint in Android Studio tell me the following warnings:
This is a Nested Layout. Layout weights require a widget to be measured twice. When a LinearLayout with non-zero weights is nested inside another LinearLayout with non-zero weights, then the number of measurements increase exponentially.
the child 1 layout is useless: This LinearLayout view is useless (no children, no background, no id, no style)
Can anyone address me the right layout to use in order to have the layout dynamically change based on the size of devices? How should I correctly set up the empty space for a linear layout case?
This is a possible solution using weights:
<LinearLayout
android:layout_width="match_parent"
android:gravity="end"
android:weightSum="1">
<!-- Your content here: -->
<View
android:layout_width="0dp"
android:layout_weight="0.8"
android:layout_gravity="end" />
</LinearLayout>
Have a look at PercentRelativeLayout.
Note: You need the Percent library to use it.

How to set the width of LinearLayout inside RelativeLayout to be independent of screen resolution?

I am a newbie in Android-programing and currently I'm building my first application. I have a LinearLayout (with several imageviews), which is situated inside of basic RelativeLayout.
The xml width and heigth settings of LinearLayout are as follows:
android:layout_width="135dp"
android:layout_height="match_parent"
The settings of imageviews inside LinearLayout look like this:
android:layout_width="match_parent"
android:layout_height="70dp"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="125dp"
android:layout_weight="3"
.....
When I start my application on small screens, it looks normal, but when the screen is big, all the pictures become very narrow (the width of LinearLayout inside RelativeLayout stays the same on small and big screen). I tried to set it in percentage, but that is not allowed. So I ask you: how can I set the width of LinearLayout to be like 25-30% of the width of parent RelativeLayout(to make my images look pretty on any device).
I know that there is a layout_weight attribute, but it doesn't seem to work with layouts inside another layouts (or maybe I have no idea what is correct or what is not).
As I know, you cant take parent layout percantage to child layout.
Linearlayout add elements to as columns or as row.
linearlayout api
Relative Layout
A Layout where the positions of the children can be described in
relation to each other or to the parent.
Relative Layout api
Why do you use linearlayout inside relative layout? In linearlayout you cant design your layout elements puting element with mouse,But in relativelayout you can.

Can't get layout to work correctly with dynamic textviews in a nested linearlayout

In an XML layout that is a RelativeLayout I have a nested LinearLayout. Within this LinearLayout I dynamically add a few TextViews and buttons. My problem is, I can't get the items to appear under each other like would naturally happen within a LinearLayout. Here is the basic setup:
LinearLayout mobLayout = (LinearLayout) findViewById(R.id.mobButtons);
mobLayout.removeAllViewsInLayout();
I remove all previous junk inside the layout because I reuse it.
mobLayout.addView(mobName);
mobLayout.addView(mobTextHP);
mobLayout.addView(fightButton);
mobLayout.addView(goBackButton);
These should appear one on top of the other, but instead appear all side by side. When I tried adding LinearLayout.LayoutParams to the first one, it wiped everything after it, or pushed it off screen, I couldn't tell.
Lastly, here is the LinearLayout XML area where these items are added:
<LinearLayout
android:id="#+id/mobButtons"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#+id/fightText">
</LinearLayout>
Thanks in advance!
Use this option for your LinearLayout
android:orientation="vertical"

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>

Automatic/dynamic margin in Android layout

I was wondering if it's possible to set an automatic/dynamic margin (padding?) between elements in an Android layout without having to do it programmatically?
For example let's say there is a horizontal LinearLayout which is set to android:layout_width="fill_parent" and that contains five elements. Is there a setting that evenly shares the remaining empty space of the LinearLayout to the margins of the child elements?
See image at http://img63.imageshack.us/img63/8/margin.png
Thanks for any help!
You could use view spacers as your margin, with the layout weight set on them.
<LinearLayout ...>
<View id=marginLeft android:layout_weight="1"/>
<Element1/>
<Element2/>
<Element3/>
<Element4/>
<Element5/>
<View id=marginRight android:layout_weight="1"/>
</LinearLayout>
This should make the two views use up any remaining space in your row. Note, the above XML will not parse :)
-- Edit
Just saw the picture. To add equal spacing between each of the elements too would just be a case of adding more spacer elements between your content elements (all with the same layout weight)
Yup. Only LinearLayouts support it. Tis called layout weight
Look for LinearLayout at http://developer.android.com/guide/topics/ui/layout-objects.html
For a good intro, look here

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