1  const { Emitter } = require('event-kit');
  2  
  3  // Extended: A container representing a panel on the edges of the editor window.
  4  // You should not create a `Panel` directly, instead use {Workspace::addTopPanel}
  5  // and friends to add panels.
  6  //
  7  // Examples: [status-bar](https://github.com/atom/status-bar)
  8  // and [find-and-replace](https://github.com/atom/find-and-replace) both use
  9  // panels.
 10  module.exports = class Panel {
 11    /*
 12    Section: Construction and Destruction
 13    */
 14  
 15    constructor({ item, autoFocus, visible, priority, className }, viewRegistry) {
 16      this.destroyed = false;
 17      this.item = item;
 18      this.autoFocus = autoFocus == null ? false : autoFocus;
 19      this.visible = visible == null ? true : visible;
 20      this.priority = priority == null ? 100 : priority;
 21      this.className = className;
 22      this.viewRegistry = viewRegistry;
 23      this.emitter = new Emitter();
 24    }
 25  
 26    // Public: Destroy and remove this panel from the UI.
 27    destroy() {
 28      if (this.destroyed) return;
 29      this.destroyed = true;
 30      this.hide();
 31      if (this.element) this.element.remove();
 32      this.emitter.emit('did-destroy', this);
 33      return this.emitter.dispose();
 34    }
 35  
 36    getElement() {
 37      if (!this.element) {
 38        this.element = document.createElement('atom-panel');
 39        if (!this.visible) this.element.style.display = 'none';
 40        if (this.className)
 41          this.element.classList.add(...this.className.split(' '));
 42        this.element.appendChild(this.viewRegistry.getView(this.item));
 43      }
 44      return this.element;
 45    }
 46  
 47    /*
 48    Section: Event Subscription
 49    */
 50  
 51    // Public: Invoke the given callback when the pane hidden or shown.
 52    //
 53    // * `callback` {Function} to be called when the pane is destroyed.
 54    //   * `visible` {Boolean} true when the panel has been shown
 55    //
 56    // Returns a {Disposable} on which `.dispose()` can be called to unsubscribe.
 57    onDidChangeVisible(callback) {
 58      return this.emitter.on('did-change-visible', callback);
 59    }
 60  
 61    // Public: Invoke the given callback when the pane is destroyed.
 62    //
 63    // * `callback` {Function} to be called when the pane is destroyed.
 64    //   * `panel` {Panel} this panel
 65    //
 66    // Returns a {Disposable} on which `.dispose()` can be called to unsubscribe.
 67    onDidDestroy(callback) {
 68      return this.emitter.once('did-destroy', callback);
 69    }
 70  
 71    /*
 72    Section: Panel Details
 73    */
 74  
 75    // Public: Returns the panel's item.
 76    getItem() {
 77      return this.item;
 78    }
 79  
 80    // Public: Returns a {Number} indicating this panel's priority.
 81    getPriority() {
 82      return this.priority;
 83    }
 84  
 85    getClassName() {
 86      return this.className;
 87    }
 88  
 89    // Public: Returns a {Boolean} true when the panel is visible.
 90    isVisible() {
 91      return this.visible;
 92    }
 93  
 94    // Public: Hide this panel
 95    hide() {
 96      let wasVisible = this.visible;
 97      this.visible = false;
 98      if (this.element) this.element.style.display = 'none';
 99      if (wasVisible) this.emitter.emit('did-change-visible', this.visible);
100    }
101  
102    // Public: Show this panel
103    show() {
104      let wasVisible = this.visible;
105      this.visible = true;
106      if (this.element) this.element.style.display = null;
107      if (!wasVisible) this.emitter.emit('did-change-visible', this.visible);
108    }
109  };