Android: Override own XML View in XML

Question

I am looking for a way to override my own XML view in android. So I only have to specify settings (like background, border, default content) once - and use it again.

The problem is that I can't find anything about it. (The things I found are about using a java class in XML to override, this is not what I want)

This is some non-working code, but I hope it explains it well enough to you:

main.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <field android:text="@string/str1" />
    <field android:text="@string/str2" />
    <field android:text="@string/str3" />
    <field android:text="@string/str4" />
    <field android:text="@string/str5" />
</LinearLayout>

code representing field (field.xml):
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/field"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@layout/field_background"
    android:text="@string/default_string"/>

As you see field itself is once defined and used many times with one customization. (Another string as text set)

This doesn't work at all, but I hope someone knows a way to make something like this work. (Without coding, just XML)

Thanks, Dennis

Ted Hopp · Accepted Answer · 2012-08-01T15:45:40.563

2

I'd suggest that you set up a style. In some file (usually styles.xml) in res/values, add a style for your field:

<style name="DefaultTextFieldStyle">
    <item name="android:id">@+id/field</item>
    <item name="android:layout_width">fill_parent</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:background">@layout/field_background</item>
</style>

Then in main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <TextView style="@style/DefaultTextFieldStyle"
        android:text="@string/str1" />
    <TextView style="@style/DefaultTextFieldStyle"
        android:text="@string/str2" />
    <TextView style="@style/DefaultTextFieldStyle"
        android:text="@string/str3" />
    <TextView style="@style/DefaultTextFieldStyle"
        android:text="@string/str4" />
    <TextView style="@style/DefaultTextFieldStyle"
        android:text="@string/str5" />
</LinearLayout>

I just copied your values, but it's wrong to have the same android:id value for several views in a layout and it's weird to have a layout as a background.

edited Aug 01 '12 at 15:45

answered Aug 01 '12 at 15:29

Ted Hopp

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I don't think the compiler'll let you define `android:id` inside a Style, anyway the idea is correct and I agree with it. I would also add style's parent, so that 'common' TextField behaviour is garanteed. – Shine Aug 01 '12 at 15:32
@Shine - I just tried defining a style containing an `@+id/foo` and both the compiler and Android Lint were perfectly happy with it. I didn't test whether the id value would actually be applied to a view, but I don't see why it wouldn't. – Ted Hopp Aug 01 '12 at 15:38
Because, as you said, it's wrong to have the same android:id value for several views..I think it's a "conceptual" error but nevermind :) – Shine Aug 01 '12 at 15:45
Styles did the job. :) The android:id I set in the "parent" TextView was because I thought the children nodes should identify it with that. (But apparently not) However, many thanks for this solution. :) – Dennis Aug 01 '12 at 16:42

score 0 · Answer 2 · edited May 23 '17 at 11:48

0

I don't know how to do what you want without code .. I would define my own custom component. Also see Different formats for different Textview defined by Custom style which shows how to style TextViews which could be what you want.

edited May 23 '17 at 11:48

Community

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answered Aug 01 '12 at 15:29

wojciii

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score 0 · Answer 3 · answered Aug 01 '12 at 15:29

No need for custom components here. If I understood your question, styles should be enough to do what are you looking for.

Just define A serie of TextViews inside the LinearLayout, and let them inheritate the common parts (layout_width, layout_height, etc.) from a Style you can define as described here.

The only changing part will be android:text, as required

Android: Override own XML View in XML

3 Answers3