Test case concat'd from fiddle (and removing 'white-space: pre-wrap' which doesn't seem necessary) attached. Note the caret is only brokenly-absent when positioned at rightmost edge of inputted text.
When the caret is positioned at the end of the editor, hasEditableStyle(node) is false for both the node and parent node here:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/editing/CaretBase.cpp?q=caretbase.cpp&sq=package:chromium&dr&l=167
(1) With text as "a" entered in the editable div, when caret is at end of input:
node = #text "autocomplete hint text"
parent node = SPAN id="after"
and (2) when it's somewhere before the end:
node = #text "a"
parent node = DIV id="editor"
Rough DOM tree below:
DIV id="editor" (editable) (focused)
#text "a"
SPAN id="after"
* #text "autocomplete hint text"
#text "\n"
So, indeed, in (1) neither the node or parent node are marked as editable when caret is at end of input. Changing #after style from:
-webkit-user-modify: read-only;
to:
-webkit-user-modify: read-write-plaintext-only;
produces a properly blinking caret (but allows editing the "autocomplete hint text", which is undesirable for intended user facing functionality).
There's some discrepancy between editing logic that properly allows inputting text, and caret shouldRepaintCaret() logic checking hasEditableStyle(). I'll look at what editing is checking, perhaps we just need to follow that more closely.
Or we may need to just walk up layout tree and just return true for shouldRepaintCaret() if there is any ancestor marked editable.
Editing logic looks like it is using EditingUtilities::isEditablePosition() which uses position.parentAnchoredEquivalent().anchorNode() and checks hasEditableStyle() on that node, which is '#text "a"' even when we are at end of input.
Perhaps we can save off the position we get in CaretBase::updateCaretRect() and pass to EditingUtilities::isEditablePosition() which has some other special-case logic we should be using around, for example, tables.
Comment 1 by einbinder@chromium.org
, Sep 10 2016