Where can I find the androidx.compose.foundation.samples.BasicTextFieldCustomInputTransformationSample

Question

I'm reading the document of InputTransformation and it leads me to a sample under - androidx.compose.foundation.samples.BasicTextFieldCustomInputTransformationSample

This is what I see from Android Studio

The thing is I can't find that sample anywhere on the internet or at least I didn't find it hard enough. Does anyone have any idea where I can see those samples?

Answer 1

Have a look at the Google Code Search. There you can find the source code of Android, AndroidX, and others. When you enter androidx.compose.foundation.samples.BasicTextFieldCustomInputTransformationSample there, you will find the BasicTextFieldSamples file line 320:

@Sampled
@Composable
fun BasicTextFieldCustomInputTransformationSample() {
    // Demonstrates how to create a custom and relatively complex InputTransformation.
    val state = remember { TextFieldState() }
    BasicTextField(state, inputTransformation = {
        // A filter that always places newly-input text at the start of the string, after a
        // prompt character, like a shell.
        val promptChar = '>'

        fun CharSequence.countPrefix(char: Char): Int {
            var i = 0
            while (i < length && get(i) == char) i++
            return i
        }

        // Step one: Figure out the insertion point.
        val newPromptChars = asCharSequence().countPrefix(promptChar)
        val insertionPoint = if (newPromptChars == 0) 0 else 1

        // Step two: Ensure text is placed at the insertion point.
        if (changes.changeCount == 1) {
            val insertedRange = changes.getRange(0)
            val replacedRange = changes.getOriginalRange(0)
            if (!replacedRange.collapsed && insertedRange.collapsed) {
                // Text was deleted, delete forwards from insertion point.
                delete(insertionPoint, insertionPoint + replacedRange.length)
            }
        }
        // Else text was replaced or there were multiple changes - don't handle.

        // Step three: Ensure the prompt character is there.
        if (newPromptChars == 0) {
            insert(0, ">")
        }

        // Step four: Ensure the cursor is ready for the next input.
        placeCursorAfterCharAt(0)
    })
}

As it turns out, it is the exact same snippet that is provided in the documentation for InputTransformation.