lexiconga-lite/src/js/StackOverflow/inputCursorManagement.js

82 lines
2.8 KiB
JavaScript

export function insertAtCursor(myField, myValue, adjustStart = 0) {
// http://stackoverflow.com/questions/11076975/insert-text-into-textarea-at-cursor-position-javascript
// IE support
if (document.selection) {
myField.focus();
sel = document.selection.createRange();
sel.text = myValue;
}
// MOZILLA and others
else if (myField.selectionStart || myField.selectionStart == '0') {
const selection = getInputSelection(myField);
selection.start += adjustStart;
myField.value = myField.value.substring(0, selection.start)
+ myValue
+ myField.value.substring(selection.end, myField.value.length);
myField.selectionStart = selection.start + myValue.length;
myField.selectionEnd = selection.start + myValue.length;
} else {
myField.value += myValue;
}
setSelectionRange(myField, myField.selectionEnd, myField.selectionEnd);
}
export function getInputSelection(el) {
// Retrieved from http://stackoverflow.com/a/4207763
var start = 0, end = 0, normalizedValue, range,
textInputRange, len, endRange;
el.focus();
if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
start = el.selectionStart;
end = el.selectionEnd;
} else {
range = document.selection.createRange();
if (range && range.parentElement() == el) {
len = el.value.length;
normalizedValue = el.value.replace(/\r\n/g, "\n");
// Create a working TextRange that lives only in the input
textInputRange = el.createTextRange();
textInputRange.moveToBookmark(range.getBookmark());
// Check if the start and end of the selection are at the very end
// of the input, since moveStart/moveEnd doesn't return what we want
// in those cases
endRange = el.createTextRange();
endRange.collapse(false);
if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
start = end = len;
} else {
start = -textInputRange.moveStart("character", -len);
start += normalizedValue.slice(0, start).split("\n").length - 1;
if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
end = len;
} else {
end = -textInputRange.moveEnd("character", -len);
end += normalizedValue.slice(0, end).split("\n").length - 1;
}
}
}
}
return { start, end };
}
export function setSelectionRange(input, selectionStart, selectionEnd) {
// Retrieved from http://stackoverflow.com/a/17858641/3508346
if (input.setSelectionRange) {
input.focus();
input.setSelectionRange(selectionStart, selectionEnd);
}
else if (input.createTextRange) {
var range = input.createTextRange();
range.collapse(true);
range.moveEnd('character', selectionEnd);
range.moveStart('character', selectionStart);
range.select();
}
}