Focus switching among focusable components doesn't work as it does with Views [192470280]

Duplicate

of 184670295

Bug

adexe s nau

Status Update

No update yet.

Description

mi...@gmail.com

created issue #1

Jun 30, 2021 06:55PM

Compose 1.0.0-beta09

Having more "focusable" composables, like TextField or Button, I'd expect that I can navigate between them using keyboard cursor keys, Tab key, or D-pad on a remote controller.

Example:

@Composable
fun SimpleFilledTextFieldSample() {
    var text by remember { mutableStateOf("Hello") }

    TextField(
        value = text,
        onValueChange = { text = it },
        label = { Text("Label") }
    )
}



@Composable
fun Main() {
    ComposeTheme{
        Column{
            SimpleFilledTextFieldSample()
            SimpleFilledTextFieldSample()
            Button(onClick = { }) {
                Text("OK")
            }
            Button(onClick = { }) {
                Text("Cancel")
            }
        }
    }
}

Currently cursor keys work within one component, but can't switch focus to next component. Also Tab key inserts tab character to text, but doesn't switch focus to next component (and Shift+Tab to previous).

I wonder how Compose is supposed to work on Android TV, and on devices without touch screen. With above code, I can switch focus to other component only by touching it.

Is there some special way to achieve such focus switching? I didn't find it. And I didn't find mention of this in documentation.

Wed Jun 30 2021 20:54:49 GMT+0200 (Central European Summer Time).png

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so...@google.com <so...@google.com> Jul 1, 2021 02:02PM

Assigned to ra...@google.com.

ma...@gmail.com <ma...@gmail.com> #2Aug 2, 2021 07:10AM

removed the dup; this is possibly about how android spans work on empty strings.

the calculation in the composable level seemed correct but the layout was not
it happens for a new line as well
one problem with both includeFontPadding true/false is that the cursor height is possibly can be visually improved to match the text ascent/descent rather than line top/bottom (might be challenging)

si...@gmail.com <si...@gmail.com> #3Aug 23, 2021 02:53PM

I do not fully understand your points, though I was wondering if a similar "trick" to measure "HHHHHHHHHHH" cannot be used here, because if I'm not mistaken the cursor gets drawn by text layout measuring on empty string.

ra...@google.com <ra...@google.com> #4Aug 23, 2021 07:44PM

StaticLayout does not call LineHeightSpan's for empty sstring (or the empty final line at the end of the string - a string that ends with "\n")

ra...@google.com <ra...@google.com> #5May 27, 2022 12:08AM

Status: Duplicate of

184670295

Project: platform/frameworks/support
Branch: androidx-main

commit b7a67dc25a34b254adbaffd02495b5c6d26ee18c
Author: siyamed <siyamed@google.com>
Date: Thu Jul 28 08:06:35 2022

Fix TextField empty line lineHeight (2)

When a line is empty (including empty text) StaticLayout
does not apply the LineHeightSpans.

This causes the line height to be different for an empty
line compared to a non empty line. The issue becomes more
visible within TextField .

This CL stores adjustment values to report the height and the
last line metrics correctly.

For the other solution option please see aosp/2170504

Performance

There are no performance differences for cases where text
is not empty or does not end with "\n"

The below numbers are for the cases where text is empty or ends with "\n"

+--------+-----------+-----------+------+
| | Before | After | Diff |
+--------+-----------+-----------+------+
| length | ns | ns | ns |
| 0 | 115,835 | 180,161 | 56% |
| 16 | 395,679 | 484,748 | 23% |
| 32 | 513,235 | 590,783 | 15% |
| 64 | 807,133 | 901,896 | 12% |
| 128 | 1,330,733 | 1,421,371 | 7% |
| 256 | 2,338,534 | 2,464,810 | 5% |
+--------+-----------+-----------+------+

Test: Added test
Test: ./gradlew text:text:test
Test: ./gradlew text:text:cAT
Test: ./gradlew compose:ui:ui-text:test
Test: ./gradlew compose:ui:ui-text:cAT
Test: Treehugger

Bug: 236615813

Change-Id: I57f8b6632f569ad06e547cf6ec83df1bc42845c9

M compose/ui/ui-text/lint-baseline.xml
M compose/ui/ui-text/benchmark/src/androidTest/java/androidx/compose/ui/text/benchmark/input/EditProcessorBenchmark.kt
M compose/ui/ui-text/benchmark/src/androidTest/java/androidx/compose/ui/text/benchmark/ParagraphBenchmark.kt
M compose/ui/ui-text/benchmark/src/main/java/androidx/compose/ui/text/benchmark/TextBenchmarkHelper.kt
M compose/ui/ui-text/src/androidAndroidTest/kotlin/androidx/compose/ui/text/ParagraphIntegrationLineHeightStyleTest.kt
M text/text/src/main/java/androidx/compose/ui/text/android/style/LineHeightStyleSpan.kt
A compose/ui/ui-text/benchmark/src/androidTest/java/androidx/compose/ui/text/benchmark/ParagraphWithLineHeightBenchmark.kt
M text/text/src/main/java/androidx/compose/ui/text/android/TextLayout.kt
M compose/ui/ui-text/benchmark/src/androidTest/java/androidx/compose/ui/text/benchmark/TextMeasurerBenchmark.kt
M compose/ui/ui-text/src/androidMain/kotlin/androidx/compose/ui/text/platform/extensions/SpannableExtensions.android.kt

https://android-review.googlesource.com/2168642

Issue 192470280