Develop Reference

Accessing a view that has a shared ID within shared layouts when only one layout is visible

In my Android app I have a layout for an activity that presents a choice.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/wrapper"
android:orientation="vertical">
<include layout="#layout/choices" />
<include layout="#layout/choice_one" />
<include layout="#layout/choice_two" />
</LinearLayout>
In layout/choices the user sees two buttons. One button shows layout/choice_one and the other shows layout/choice_two. (The parent in layout/choice_one and layout/choice_two is initially set to android:visibility=gone.)
So when a user chooses either choice_one or choice_two, essentially I'm setting the visibility to VISIBLE. That works great.
The issue is that inside of both choice_one and choice_two I have shared elements with the same ID. For example I have a TextView with ID header. (I did this because I figured only one of those layouts would be visible and they use the same things.)
The issue is that I use Butterknife, and it seems like if I Bind header, when I set the visibility on choice_one or choice_two, I have a 50/50 chance of correctly calling header.setText("Blah") on the appropriate header element.
I'm sure I can get around this by giving unique IDs to all elements in the layouts or ditching Butterknife and using findViewById instead. But is there another way I can target a shared ID inside of a layout without ditching Butterknife or my shared layouts?

I figured this out. (Writing it out helped, so I'll keep it here in case someone else stumbles upon it.) Instead of using include in xml and inflating layouts there, I just subclassed ViewGroup for my two layouts and added them to wrapper:
ChoiceOne choiceOne = new ChoiceOne();
wrapper.addView(choiceOne);

Rotated ListFragment disappears when empty view displayed after Filter

Just to be clear, we're talking about an XML rotated view here, not the effects of rotating the device. I have a SlidingDrawer that contains a ListFragment. The ListFragment implements the Filterable interface so that users can search its contents by providing a string input through an EditText.
The relevant layout is included below. Because the SlidingDrawer class was deprecated in API 17, the source code was copied over an accessed via a local class. That's why the name of that view looks like a custom class when really it's not.
<com.example.echo.views.SlidingDrawer
android:id="#+id/left_sliding_drawer"
android:layout_height="match_parent"
android:layout_width="wrap_content"
android:handle="#+id/left_handle"
android:orientation="horizontal"
android:content="#+id/people_fragment_container"
android:rotation="180">
<LinearLayout
android:id="#id/left_handle"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/people_tab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/people_map_tab_grey"
android:rotation="180"
android:contentDescription="#string/people_tab"/>
</LinearLayout>
<FrameLayout
android:id="#+id/people_fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</com.example.echo.views.SlidingDrawer>
What happens is, when the users provides input and filters the list such that there are no matching results, i.e., the ListView is empty and size is 0, the entire SlidingDrawer disappears.
Some things I've noticed in trying to fix this:
I am pretty sure this is related to displaying the empty view and/or whatever layout change occurs when it is displayed. If I simply do not set an empty view for the ListFragment the issue does not occur.
I am also pretty sure the effects are related to the fact that the SlidingDrawer is being rotated by 180 degrees since, if I remove the rotation attribute, the issue also does not occur. However, because SlidingDrawer in its default state only opened right to left, this drawer applies the XML attribute android:rotation="180" to flip the view so that it can be opened left to right. This must remain since there is other stuff on the right side of the screen that cannot be moved.
I'm not sure what is making the view disappear or where to start fixing it. I've trying fixing the child views' sizes by overriding onMeasure, onSizeChanged, and onLayout but cannot find anything that solves the issue.
Any ideas are appreciated.

Android how to draw several lines on an ImageView as another layer?

I would like to have the app draw several lines for showing user directions by using a background image as a base view and the app "draws" onto it in another layer on top of the background ImageView. Several lines would be made for the objectives to be met, and also in a specific location, so it has to have several layers too right??
I found a trick for drawing a single line using XML
<View
android:id="#+id/line"
android:layout_width="2dip"
android:layout_height="300dip"
android:background="#000000"
/>
But that code doesn't show positions and not in a layered form.
Update :
I would like the lines to appear through drawing, not through another picture

You can make a custom SurfaceView class, set the image as background and paint your lines on its Canvas. If I correctly understood what you want to achieve, that's probably the easiest way.
SurfaceView is a widget from the Android framework. Extend it to make your own: MySurfaceView extends SurfaceView. Then override public void onDraw(Canvas canvas), as android_user77 noted. Use this canvas object to paint on. Finally, add your class in the layout xml:
<com.your.app.MySurfaceView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/my_image" />
For details as why to use SurfaceView instead of View:
Difference between SurfaceView and View?

You can extend view and do the drawing by overriding the onDraw method

Use FrameLayout to create many "layers". I do not think you want to draw anything on the view. So do not use onDraw(), SurfaceView...
The code is like:
<FrameLayout ...>
<ImageView id="#+id/layer1"...>
<ImageView id="#+id/layer2"...>
</FrameLayout>

What should my Android Layout look like?

I recently asked a question about how to add a view on top of a view, after asking that I realized I needed to added a better layout to my app before proceeding further.
I was reading Android Layout Tricks but noticed it was specifically for text views and image views. I'm looking to do it with two custom views. So I decided to whip up a quick image in paint to hopefully show more clearly of what I'm wanting to do.
This is how I want my layout to split the views. :
This is how it would look with the views drawn. Obviously the purple and blue boundaries would be the background color (greyish). The data above simply displays the y-intercept of the graph drawn with respective color. (So there would be multiple graph views drawn on top of each other)
So my question is, what would my main content view look like? I assume it would have a Linear layout but I'm rather new to these layouts.
EDIT
Using TextViews I'm able to come up with something similar using the following XML:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:text="Data Placeholder"
android:background="#733674"
android:textSize="15pt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="20"/>
<TextView
android:text="Graph Placeholder"
android:background="#374F82"
android:textSize="15pt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="80"/>
</LinearLayout>
</LinearLayout>
So The only question that really remains is, am I supposed to use TextViews? Meaning in my Activity am I able to add my custom views where these TextViews are? Or am I supposed to add my custom view to the XML?
Ie.
<DataView
android:text="Data Placeholder"
android:background="#733674"
android:textSize="15pt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="20"/>
<GraphView
android:text="Graph Placeholder"
android:background="#374F82"
android:textSize="15pt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="80"/>
My custom views are written in Java and I'm not sure how I would let the layout know where the views are located if I was to do it this way.

Try this: http://developer.android.com/resources/tutorials/views/hello-linearlayout.html
It has some very useful information which might help you out in regards to layout_weight as Michell Bak mentioned in the comment.
And here's the page for the Hello Views:
http://developer.android.com/resources/tutorials/views/index.html
Not to be rude, but it would be much better for you to peruse these and learn the xml on your own. That way you can actually understand it and be better able to re-create it later.
I was quite overwhelmed at first with all the code I didn't understand (including xml files), but with a little practice it becomes very easy - just time consuming.
The main thing I'm confused about is what kind of View to put in the
layout. In the examples they use TextView or ImageView, but mine is a
custom view
Well, for your "Custom Data View", you would use a LinearLayout with android:layout_width="fill_parent" and android:layout_height="fill_parent" and android:layout_weight="1" and android:background="#BA4AAB" (See http://www.colorpicker.com/)
Then for your Custom Graph View, I would use:
android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="4" android:background="#7D4ABA"
Note the layout_weight and background values I put are kind of guesses, you might have to tweak them some to match what you want.
The two linearlayouts that I mentioned would be inside one larger LinearLayout with android:orientation="vertical"
Then for the data in the top, you would use 4 text Views, and in code, you'd use setText(...) on those text views to put your data in.
In the xml for textview1, you would add android:id="#+id/textview1" then in code add TextView textview1 = (TextView)findviewbyId(R.id.textview1); then textview1.setText(myString);
For the graph in the bottom part, you would use 2 views for the base of the graph, and set there android:layout_width and android:layout_height to whatever suits you using dip, dp, or px units.
For the lines that you draw, I believe you would have to use the canvas class with a bitmap and call canvas.drawLine(...) (see http://developer.android.com/reference/android/graphics/Canvas.html)

How do I add a tween animation to my custom view?

This is my first Android project, so bear with me. I created a custom view ("GameBoard" extends View) for drawing my game board and pieces by overriding the OnDraw. It all works fine. However, I'd like to add a tween-animated "You win" graphic at the end of the game. However, I can't figure out how to add an ImageView to my GameBoard view.
I read that I could use an XML file and add my custom view to it, but it didn't work. Here's my XML code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#001133" >
<view Class = "com.myname.firstgame.GameBoard"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
</view>
</RelativeLayout>
I also tried it without the "view Class =" in the view tag. I also tried it without the ".GameBoard" in the view tag and specifying it in the "android:id=" tag. (All these attempts came from Google searches.)
If I can get it to work, I figure I can add an ImageView with my bitmap as the background, place it in the right spot, and animate it. I do a similar thing for my title screen and it works fine, but it uses an XML natively, without a custom view. (In hindsight, I'm wondering if I should have used XML rather than a custom view for the game board, but that's another matter.)
Can anyone help, please?

This seems to answer your question.
http://sankarganesh-info-exchange.blogspot.com/2011/04/performing-animation-in-android.html
just call the target.startAnimation() method when your user wins / loses / whatevers your game