1 files changed, 189 insertions, 0 deletions
diff --git a/devtools/client/accessibility/picker.js b/devtools/client/accessibility/picker.js
new file mode 100644
index 0000000000..49ba2b5bfc
--- /dev/null
+++ b/devtools/client/accessibility/picker.js
@@ -0,0 +1,189 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {
+  L10N,
+} = require("resource://devtools/client/accessibility/utils/l10n.js");
+
+class Picker {
+  constructor(panel) {
+    this._panel = panel;
+
+    this.isPicking = false;
+
+    this.onPickerAccessibleHovered = this.onPickerAccessibleHovered.bind(this);
+    this.onPickerAccessiblePicked = this.onPickerAccessiblePicked.bind(this);
+    this.onPickerAccessiblePreviewed =
+      this.onPickerAccessiblePreviewed.bind(this);
+    this.onPickerAccessibleCanceled =
+      this.onPickerAccessibleCanceled.bind(this);
+  }
+
+  get toolbox() {
+    return this._panel._toolbox;
+  }
+
+  get accessibilityProxy() {
+    return this._panel.accessibilityProxy;
+  }
+
+  get pickerButton() {
+    return this.toolbox.pickerButton;
+  }
+
+  get _telemetry() {
+    return this._panel._telemetry;
+  }
+
+  release() {
+    this._panel = null;
+  }
+
+  emit(event, data) {
+    this.toolbox.emit(event, data);
+  }
+
+  /**
+   * Select accessible object in the tree.
+   * @param  {Object} accessible
+   *         Accessiblle object to be selected in the inspector tree.
+   */
+  select(accessible) {
+    this._panel.selectAccessible(accessible);
+  }
+
+  /**
+   * Highlight accessible object in the tree.
+   * @param  {Object} accessible
+   *         Accessiblle object to be selected in the inspector tree.
+   */
+  highlight(accessible) {
+    this._panel.highlightAccessible(accessible);
+  }
+
+  getStr(key) {
+    return L10N.getStr(key);
+  }
+
+  /**
+   * Override the default presentation of the picker button in toolbox's top
+   * level toolbar.
+   */
+  updateButton() {
+    this.pickerButton.description = this.getStr("accessibility.pick");
+    this.pickerButton.className = "accessibility";
+    this.pickerButton.disabled = !this.accessibilityProxy.enabled;
+    if (!this.accessibilityProxy.enabled && this.isPicking) {
+      this.cancel();
+    }
+  }
+
+  /**
+   * Handle an event when a new accessible object is hovered over.
+   * @param  {Object} accessible
+   *         newly hovered accessible object
+   */
+  onPickerAccessibleHovered(accessible) {
+    if (accessible) {
+      this.emit("picker-accessible-hovered", accessible);
+      this.highlight(accessible);
+    }
+  }
+
+  /**
+   * Handle an event when a new accessible is picked by the user.
+   * @param  {Object} accessible
+   *         newly picked accessible object
+   */
+  onPickerAccessiblePicked(accessible) {
+    if (accessible) {
+      this.select(accessible);
+    }
+    this.stop();
+  }
+
+  /**
+   * Handle an event when a new accessible is previewed by the user.
+   * @param  {Object} accessible
+   *         newly previewed accessible object
+   */
+  onPickerAccessiblePreviewed(accessible) {
+    if (accessible) {
+      this.select(accessible);
+    }
+  }
+
+  /**
+   * Handle an event when picking is cancelled by the user.s
+   */
+  onPickerAccessibleCanceled() {
+    this.cancel();
+    this.emit("picker-accessible-canceled");
+  }
+
+  /**
+   * Cancel picking.
+   */
+  async cancel() {
+    await this.stop();
+  }
+
+  /**
+   * Stop picking.
+   */
+  async stop() {
+    if (!this.isPicking) {
+      return;
+    }
+
+    this.isPicking = false;
+    this.pickerButton.isChecked = false;
+
+    await this.accessibilityProxy.cancelPick();
+    this._telemetry.toolClosed("accessibility_picker", this);
+    this.emit("picker-stopped");
+  }
+
+  /**
+   * Start picking.
+   * @param  {Boolean} doFocus
+   *         If true, move keyboard focus into content.
+   */
+  async start(doFocus = true) {
+    if (this.isPicking) {
+      return;
+    }
+
+    this.isPicking = true;
+    this.pickerButton.isChecked = true;
+
+    await this.accessibilityProxy.pick(
+      doFocus,
+      this.onPickerAccessibleHovered,
+      this.onPickerAccessiblePicked,
+      this.onPickerAccessiblePreviewed,
+      this.onPickerAccessibleCanceled
+    );
+
+    this._telemetry.toolOpened("accessibility_picker", this);
+    this.emit("picker-started");
+  }
+
+  /**
+   * Toggle between starting and canceling the picker.
+   * @param  {Boolean} doFocus
+   *         If true, move keyboard focus into content.
+   */
+  toggle(doFocus) {
+    if (this.isPicking) {
+      return this.cancel();
+    }
+
+    return this.start(doFocus);
+  }
+}
+
+exports.Picker = Picker;