Use full height of the glyph for caret height on Android #30991
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GaryQian
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a: text input
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justinmc
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Something else we can do here is to also center the caret vertically instead of scaling off of the top left corner. This allows for adjustment of the caret height, which is not currently possible due to the origin of the caret. |
GaryQian
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)" This reverts commit 96e1fc9.
GaryQian
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The caret on Android has since drifted from canonical carets on Android (comparing against stock Google apps, and blank Android textfields). Flutter's carets are significantly shorter and are not centered. This problem becomes worse when mixing multiple scripts together such as english+chinese.
This PR changes the non-iOS caret (iOS caret has special handling) to instead be the full height of the glyph at the current caret position. This causes the caret to always fully cover the glyph as well as look much closer to the stock Android behavior.
To achieve this, we add
getFullHeightForCaret()to TextPainter, which returns the height the caret should be if it were to fully cover the height of the glyph. To prevent multiple calculations of the boxes around the glyphs, the metrics are cached and only recalculated if the TextPosition and caret proto passed in differ.This fixes #23934 (as well as numerous duplicates of it)
Since this changes the caret behavior, it will likely break some golden/scuba tests, although this should be a strict improvement in fidelity compared to the current behavior. I will still label it breaking change, although there are no API breakages.