[caret-color] Clip the override paint to the caret rect.#59798
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With current paint code, we noticed that when the block caret first moves past the end of the text (no character is overlapped) and then moves back to a position inside the text, every glyph of the fragment gets re-painted in the second caret-color. This is due to the call of text_painter.Paint() with slice [char_start, char_end] is honored only when font.DrawText() actually re-shapes. When CachedTextBlob() returns non-null, the slice is discarded and the entire cached blob is redrawn with the override fill color. The solution here is to clip the override paint to the caret rect. Bug: 498556169 Change-Id: I30ad92029a23f502226058eaf2db0bbe180a3b45 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7829948 Reviewed-by: Stephen Chenney <schenney@chromium.org> Reviewed-by: Kent Tamura <tkent@chromium.org> Commit-Queue: Ziran Sun <zsun@igalia.com> Cr-Commit-Position: refs/heads/main@{#1629124}
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With current paint code, we noticed that when the block caret
first moves past the end of the text (no character is overlapped)
and then moves back to a position inside the text, every glyph of
the fragment gets re-painted in the second caret-color.
This is due to the call of text_painter.Paint() with slice
[char_start, char_end] is honored only when font.DrawText() actually
re-shapes. When CachedTextBlob() returns non-null, the slice is
discarded and the entire cached blob is redrawn with the override
fill color.
The solution here is to clip the override paint to the caret rect.
Bug: 498556169
Change-Id: I30ad92029a23f502226058eaf2db0bbe180a3b45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7829948
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Ziran Sun <zsun@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1629124}