FindUnusedResources

Find and remove unused resources in an Android project

Removes the following resources defined in any .xml file located in any project/res/values* directory

string, dimen, color, string-array, array, style

Removes the following resources located in any project/res/drawable* directory:

.png, .xml

Build

cd src/
javac FindUnusedResources.java

Run

java FindUnusedResources PATH
- where PATH is the path to your Android project (should have AndroidManifest.xml file in it)
- optionally, add "noprompt" after PATH to remove unused resources w/out prompting

WARNING

By default, this program will by allow you to view unused resources before removing anything. However, to be same please sure to start with a clean workspace (ie: no outstanding changes) under source control or have a copy of the project backed up! That way, if it removes something you needed, you can always revert easily.

DETAILS

Here's what this program is doing in steps.. see the source code for the low-level details!

STEP 1 - build up a list of all resources used by the app

Index the contents of all .xml files in all res/values*/ folders

eg:
res/values/strings.xml
    <string name="text_log_in">Sign In</string>
    <string name="text_reset">Reset</string>

res/values/colors.xml
    <color name="dark_grey">#ACACAA</color>
	<color name="white">#FFFFFF</color>
	
res/values/dimens.xml
    <dimen name="text_8">8dp</dimen>
	<dimen name="text_10">10dp</dimen>

Index filenames in all res/drawable*/ folders

eg:
res/drawable/selector1.xml
res/drawable-xxhdpi/icon.png

Index filenames in all res/layout*/ folders

eg:
res/layout/dialog1.xml
res/layout/fragment1.xml

STEP 2 - find number of uses for each of the indexed resources

search through all .java and .xml files in the project, looking for any uses of the indexed resources

There's a few different ways a resource can be referenced in Android.. here's what I'm looking for.

.java:

R.<type>.<value> (where <type> could be "string", "dimen", "color", etc)
R.id.<value>

.xml

@<type>/<value> (where <type> could be "string", "dimen", "color", etc)
@id/<value>
- additionally, the following are looked at for <style>'s:
   parent=<value>
   @<value>.

STEP 3 - remove or delete resources with no references

STEP 4 - repeat step 2 & 3 until we've removed all unused resources

This step is necessary because a resource may be referenced by another resource. For example, an image could be referenced by a layout. If the layout isn't referenced anywhere, it'll be removed in the first pass. But, since the image was referenced, it won't be removed.

On the second pass, the unreferenced image will be removed.. and so on.

OUTPUT

The app will print some statistics while it runs. See the example output below:

(UPDATE: output has changed slightly since I'm now prompting the user after each PASS)

Indexing resources...
got 368 string resources
got 98 dimen resources
got 73 color resources
got 2 string-array resources
got 38 style resources
got 125 layout resources
got 297 drawable resources

PASS 1...............................
Removed 61 string resources
Removed 5 dimen resources
Removed 8 color resources
Removed 57 drawable resources

PASS 2..............................
Removed 3 color resources
Removed 3 drawable resources

PASS 3...........................
Removed 2 drawable resources

PASS 4............................
Removed 1 color resources

PASS 5.............................
DONE! Removed 80 TOTAL resources
-> 12 color resources
-> 61 string resources
-> 62 drawable resources
-> 5 dimen resources