[react-packager][streamline oss] Move open sourced JS source to react-native-github

Libraries/vendor/document/selection/DocumentSelectionState.js

@@ -0,0 +1,156 @@
+/**
+ * @generated SignedSource<<1f058815818e10d01d2ee1f2f70d0fb1>>
+ *
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * !! This file is a check-in of a static_upstream project!      !!
+ * !!                                                            !!
+ * !! You should not modify this file directly. Instead:         !!
+ * !! 1) Use `fjs use-upstream` to temporarily replace this with !!
+ * !!    the latest version from upstream.                       !!
+ * !! 2) Make your changes, test them, etc.                      !!
+ * !! 3) Use `fjs push-upstream` to copy your changes back to    !!
+ * !!    static_upstream.                                        !!
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ *
+ * @providesModule DocumentSelectionState
+ * @typechecks
+ */
+
+var mixInEventEmitter = require('mixInEventEmitter');
+
+/**
+ * DocumentSelectionState is responsible for maintaining selection information
+ * for a document.
+ *
+ * It is intended for use by AbstractTextEditor-based components for
+ * identifying the appropriate start/end positions to modify the
+ * DocumentContent, and for programatically setting browser selection when
+ * components re-render.
+ */
+class DocumentSelectionState {
+  /**
+   * @param {number} anchor
+   * @param {number} focus
+   */
+  constructor(anchor, focus) {
+    this._anchorOffset = anchor;
+    this._focusOffset = focus;
+    this._hasFocus = false;
+  }
+
+  /**
+   * Apply an update to the state. If either offset value has changed,
+   * set the values and emit the `change` event. Otherwise no-op.
+   *
+   * @param {number} anchor
+   * @param {number} focus
+   */
+  update(anchor, focus) {
+    if (this._anchorOffset !== anchor || this._focusOffset !== focus) {
+      this._anchorOffset = anchor;
+      this._focusOffset = focus;
+      this.emit('update');
+    }
+  }
+
+  /**
+   * Given a max text length, constrain our selection offsets to ensure
+   * that the selection remains strictly within the text range.
+   *
+   * @param {number} maxLength
+   */
+  constrainLength(maxLength) {
+    this.update(
+      Math.min(this._anchorOffset, maxLength),
+      Math.min(this._focusOffset, maxLength)
+    );
+  }
+
+  focus() {
+    if (!this._hasFocus) {
+      this._hasFocus = true;
+      this.emit('focus');
+    }
+  }
+
+  blur() {
+    if (this._hasFocus) {
+      this._hasFocus = false;
+      this.emit('blur');
+    }
+  }
+
+  /**
+   * @return {boolean}
+   */
+  hasFocus() {
+    return this._hasFocus;
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCollapsed() {
+    return this._anchorOffset === this._focusOffset;
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isBackward() {
+    return this._anchorOffset > this._focusOffset;
+  }
+
+  /**
+   * @return {?number}
+   */
+  getAnchorOffset() {
+    return this._hasFocus ? this._anchorOffset : null;
+  }
+
+  /**
+   * @return {?number}
+   */
+  getFocusOffset() {
+    return this._hasFocus ? this._focusOffset : null;
+  }
+
+  /**
+   * @return {?number}
+   */
+  getStartOffset() {
+    return (
+      this._hasFocus ? Math.min(this._anchorOffset, this._focusOffset) : null
+    );
+  }
+
+  /**
+   * @return {?number}
+   */
+  getEndOffset() {
+    return (
+      this._hasFocus ? Math.max(this._anchorOffset, this._focusOffset) : null
+    );
+  }
+
+  /**
+   * @param {number} start
+   * @param {number} end
+   * @return {boolean}
+   */
+  overlaps(start, end) {
+    return (
+      this.hasFocus() &&
+      this.getStartOffset() <= end && start <= this.getEndOffset()
+    );
+  }
+}
+
+mixInEventEmitter(DocumentSelectionState, {
+  'blur': true,
+  'focus': true,
+  'update': true
+});
+
+module.exports = DocumentSelectionState;
+