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-rw-r--r--ext/js/util.js70
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diff --git a/ext/js/util.js b/ext/js/util.js
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+++ b/ext/js/util.js
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+/*
+ * Copyright (C) 2016 Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+function getRangeAtPoint(point, lookAhead) {
+ const range = document.caretRangeFromPoint(point.x, point.y);
+ if (range === null) {
+ return null;
+ }
+
+ const node = range.startContainer;
+ if (node.nodeType !== 3 /* TEXT_NODE */) {
+ return null;
+ }
+
+ const offset = range.startOffset;
+ const length = Math.min(node.length - offset, lookAhead);
+ if (length === 0) {
+ return null;
+ }
+
+ range.setEnd(node, offset + length);
+ return range;
+}
+
+function getRangePaddedRect(range) {
+ const node = range.startContainer;
+ const startOffset = range.startOffset;
+ const endOffset = range.endOffset;
+
+ range.setStart(node, Math.max(0, startOffset - 1));
+ range.setEnd(node, Math.min(node.length, endOffset + 1));
+ const rect = range.getBoundingClientRect();
+ range.setStart(node, startOffset);
+ range.setEnd(node, endOffset);
+
+ return rect;
+}
+
+function getPopupPositionForRange(popup, range, offset) {
+ const rangeRect = range.getBoundingClientRect();
+ const popupRect = popup.getBoundingClientRect();
+
+ let posX = rangeRect.left;
+ if (posX + popupRect.width >= window.innerWidth) {
+ posX = window.innerWidth - popupRect.width;
+ }
+
+ let posY = rangeRect.bottom + offset;
+ if (posY + popupRect.height >= window.innerHeight) {
+ posY = rangeRect.top - popupRect.height - offset;
+ }
+
+ return {x: posX, y: posY};
+}