I have a list that is populated by a listadapter that specifies a layout like so:
SimpleCursorAdapter trips =
new SimpleCursorAdapter(this, R.layout.it_menu_home_row, tripsCursor, from, to);
Inside of that layout is a textview. I would like to be able to dynamically change the width of that textview through code. I have tried just referencing the textview ID with findViewById, but when I try to manipulate it, I get a null pointer exception.
Is there a simple way reference the textview of a listadapters layout?
I am trying to reference the text view like I would if it was sitting in the base layout of the activity:
TextView tv = (TextView)findViewById(R.id.myTV);
I don't know if I have to somehow iterate through each of the list items and manually set the textView that way (and if I do I am not sure how), or if I just have to reference it once, etc
When you use SimpleCursorAdapter you provide the textFields via the constructor itself. In the snippet you have given, to should be an array of id's of the TextView's present.
For example if your layout file has a TextView with the id: "#+id/my_textfield" then you should pass in your constructor an array: int to[]=new int[]{R.id.my_textfield};
Related
I get the list of elements from the HTTP response, then I want to dynamically insert that list into the textview inside the "box" that you can see, currently it just inserts a string and overlaps them one over the other. I tried changing the layout (all three constraint, relative and linear) and it didn't help. Does anyone know how to position them dynamicly inside the boxes and not overlap but have margins like in the second picture? Otherwise, inside the project, I use a constrain layout.
Here is my code:
RelativeLayout parentLayout = (RelativeLayout) findViewById(R.id.layout);
int size = response.toArray().length;
final TextView[] tv = new TextView[size];
TextView temp;
for (int i = 0; i < size; i++)
{
temp = new TextView(Activity.this);
temp.setText(response.get(i).getName());
parentLayout.addView(temp);
tv[i] = temp;
}
Here is the picture how it looks right now:
And here is the picture how I want it to looks like:
This sounds like a typical ListView use case.
Firstly, I'd suggest you go through the documentation -
https://developer.android.com/reference/android/widget/ListView
You can see an implementation example of a list view with an array of strings here -
https://androidexample.com/Create_A_Simple_Listview_-_Android_Example/index.php?view=article_discription&aid=65
In general, you choose the UI of your item and the listView populates the view to each item in your list (each string in your case).
In the adapter, you give each item the data it needs for the UI.
I would suggest you to use RecyclerView for this type of task. You may use ListView as well.
But RecyclerView is more flexible and advanced than ListView.
Create a simple layout or xml file for your row item to be shown in RecyclerView.
Add that row xml file in onCreateViewHolder method. And inside method onBindViewHolder do necessary task like for example, showing name in the list for each position.
Go to this link for your reference : https://developer.android.com/guide/topics/ui/layout/recyclerview
Instead of Array<String> you can use Array<CustomModel> as well depending on your requirement.
Simple example of RecyclerView with model objects as list : https://www.javatpoint.com/android-recyclerview-list-example
Well, the proper way to do what you need is use ListView or RecyclerView.
Anyway, if you want to use your current solution, you need to specify the position of each TextView.
For example, assign an ID to each textview you create and then set the position of it under the previous one. Here you can find how to do that.
So, what I'd like is: defining a component, which includes TextView-s and an ImageView. This is an item, which I'd like to add to a (for example Linear) layout, so I can display all the custom items, I added one after the other.
The point is, that these items have to be editable, because a database query result will define their text content and the image.
Your custom component should be a ViewGroup itself. You can add any number of TextViews and ImageViews to it, and access them by their ID.
MyCustomViewGroup component = (MyCustomViewGroup)linearLayout.findViewById(...);
TextView textView1 = (TextView)component.findViewById(...);
ImageView imageView = (ImageView)component.findViewById(...);
You can go for the XML approach for defining your component. For instance, you can define your component as a LinearLayout, then add all the elements (TextViews, ImageViews) you need to that layout.
As for the "editable" part, just provide your elements with an id property
android:id="#+id/my_view"; that way you may obtain them through a findViewById(R.id.my_view) call.
You cast the results to whatever View implementation you are expecting, then change it's text/content/image with the interpreted results from your query.
I'm not sure how to ask this question exactly, but I'll give it a try.
Here's what I'm trying to do, in one Activity.
Build a Grid, that contains [x] rows of 3 columns each, with this content
[a TextView (containing a name)] [a Spinner (containing a list of states)] [an EditText]
How to start ? The Views I can create programmatically, that's not a problem, I even store them in 3 array lists for later easy reference, but I can't see how to do it right.
Should I create an xml layout with e.g. (and pseudocode)
LinearLayout (horizontal)
TextView ...
Spinner ...
EditText ...
/LinearLayout
and try to inflate it in the loop I use to create each row, and setting the id of each view in a standard way (e.g. viewName[x] where x is the current "i" from my for, but is it of any use?), as we do for example for an ExpendableList Adapter's groups/childs ?
Or is there a way to actually use a GridView/GridLayout to do that (in this case, being in my Activity, how do I put each specific created View into the correct GridView/GridLayout) ?
Or still another way I don't suspect at all ?
Thanks in advance
if you want to add views programatically then, just create a layout.xml with 3 Linearlayouts(horizontal) in it. Also assign id to those LinearLayouts. Then in your java code, just find the views and call addView() on those LinearLayouts.
Example:
LinearLayout ll_1 = (LinearLayout)findViewById(R.id.linearlayout1);
LinearLayout ll_2 = (LinearLayout)findViewById(R.id.linearlayout2);
LinearLayout ll_3 = (LinearLayout)findViewById(R.id.linearlayout3);
...
ll_1.addView(new TextView(this));
ll_1.addView(new Spinner(this));
ll_1.addView(new EditText(this));
...
In detail, say for example, if i want to add spinner to LinearLayout, programatically then,
You need to get layout
LinearLayout linearLayout = findViewById(R.id.layoutID);
Create spinner as below:
Spinner spinner = new Spinner(this);
spinner .setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));
ArrayAdapter spinnerArrayAdapter = new ArrayAdapter(this,
android.R.layout.simple_spinner_dropdown_item, spinnerList);
spinner.setAdapter(spinnerArrayAdapter);
Then add spinner to view
linearLayout.addView(spinner);
Im using textview and edittexts to make a listview and using a hashmap to copy paste the layout. Now how do i get the values from the edit texts ? I tried it but it doesn't work because everytime we're using a new hashmap variable to create a copy and i didn't find anything like an array of hashmap variables.. Help needed.
My xml files :
MarksList>res>layout>marks_list_main :
Suppose you have added a LinearLayout as list item and on that Layout there is an edittext and a textview
LinearLayout layout=(LinearLayout) listView.getItemAtPosition(0);
EditText text = (EditText) layout.getChildAt(0); //Assuming you added EditText first
String s=text.getText().toString()
I have an android app which asks a question followed by x number of options.
Each option contains a textview, ImageView and a radio button.
The value of x (i.e. the number of options) is not constant. I want to dynamically add UI content to satisfy this requirement.
At the moment I have written the code in the layout's xml to display a maximum of 4 options. If number of options is 2 I hide the options 3 and 4 using something like
tvoption1.setVisibility(View.GONE);
tvoption2.setVisibility(View.GONE);
However this is not very scalable. Can anyone tell me how to add options for java dynamically. Or is there a better approach?
A View can be added at runtime by using the inflater like this:
LinearLayout linearLayout = (LinearLayout)inflater.inflate(R.layout.news_categories_item, null);
TextView categoryValueTextView = (TextView)linearLayout.findViewById(R.id.news_category_item_value);
mMainLinearLayout.addView(categoryValueTextView);
In this example, a LinearLayout containing a TextView is inflated. A reference to the constituent TextView is then obtained, and the TextView is dynamically added (at runtime) to the main linear layout (mMainLinearLayout).
The inflater object may be obtained in an Activity by using getLayoutInflater().
create your row layout separately, from the main xml
Get LayoutInflater service from context:
LayoutInflater inflater=(LayoutInflater)getSystemService(LAYOUT_INFLATE_SERVICE);
use following method to addview to main xml, I assume you have parent layout llParent in xml and you want to add items in this llPaent, from list list.
for(int i=0;i<list.size();i++)
{
LinearLayout llView=(LinearLayout)inflater.inflate(R.layout.row);
//get view id and set values
TextView txt=(TextView)llView.findViewById(R.id.text);
}
A ListView is a good view for displaying several similar items. Here is a tutorial (Other views with adapters are good too, such as GridView or Gallery).
You will probably want to create your own adapter for the list, so you can display all three views (checkbox, image and text) as one item, but there are lots of examples on that available on the net as well as here on SO.