phorge-phorge/webroot/rsrc/js/application/diff/DiffChangeset.js

/**
 * @provides phabricator-diff-changeset
 * @requires javelin-dom
 *           javelin-util
 *           javelin-stratcom
 *           javelin-install
 *           javelin-workflow
 *           javelin-router
 *           javelin-behavior-device
 *           javelin-vector
 *           phabricator-diff-inline
 *           phabricator-diff-path-view
 *           phuix-button-view
 *           javelin-external-editor-link-engine
 * @javelin
 */

JX.install('DiffChangeset', {

  construct : function(node) {
    this._node = node;

    var data = this._getNodeData();

    this._renderURI = data.renderURI;
    this._ref = data.ref;
    this._loaded = data.loaded;
    this._treeNodeID = data.treeNodeID;

    this._leftID = data.left;
    this._rightID = data.right;

    this._displayPath = JX.$H(data.displayPath);
    this._pathParts = data.pathParts;
    this._icon = data.icon;

    this._editorURITemplate = data.editorURITemplate;
    this._editorConfigureURI = data.editorConfigureURI;
    this._showPathURI = data.showPathURI;
    this._showDirectoryURI = data.showDirectoryURI;

    this._pathIconIcon = data.pathIconIcon;
    this._pathIconColor = data.pathIconColor;
    this._isLowImportance = data.isLowImportance;
    this._isOwned = data.isOwned;
    this._isLoading = true;

    this._inlines = null;

    if (data.changesetState) {
      this._loadChangesetState(data.changesetState);
    }

    JX.enableDispatch(window, 'selectstart');

    var onselect = JX.bind(this, this._onClickHeader);
    JX.DOM.listen(
      this._node,
      ['mousedown', 'selectstart'],
      'changeset-header',
      onselect);
  },

  members: {
    _node: null,
    _loaded: false,
    _sequence: 0,
    _stabilize: false,

    _renderURI: null,
    _ref: null,
    _rendererKey: null,
    _highlight: null,
    _requestDocumentEngineKey: null,
    _responseDocumentEngineKey: null,
    _availableDocumentEngineKeys: null,
    _characterEncoding: null,
    _undoTemplates: null,

    _leftID: null,
    _rightID: null,

    _inlines: null,
    _visible: true,

    _displayPath: null,

    _changesetList: null,
    _icon: null,

    _editorURITemplate: null,
    _editorConfigureURI: null,
    _showPathURI: null,
    _showDirectoryURI: null,

    _pathView: null,

    _pathIconIcon: null,
    _pathIconColor: null,
    _isLowImportance: null,
    _isOwned: null,
    _isHidden: null,
    _isSelected: false,
    _viewMenu: null,

    getEditorURITemplate: function() {
      return this._editorURITemplate;
    },

    getEditorConfigureURI: function() {
      return this._editorConfigureURI;
    },

    getShowPathURI: function() {
      return this._showPathURI;
    },

    getShowDirectoryURI: function() {
      return this._showDirectoryURI;
    },

    getLeftChangesetID: function() {
      return this._leftID;
    },

    getRightChangesetID: function() {
      return this._rightID;
    },

    setChangesetList: function(list) {
      this._changesetList = list;
      return this;
    },

    setViewMenu: function(menu) {
      this._viewMenu = menu;
      return this;
    },

    getIcon: function() {
      if (!this._visible) {
        return 'fa-file-o';
      }

      return this._icon;
    },

    getColor: function() {
      if (!this._visible) {
        return 'grey';
      }

      return 'blue';
    },

    getChangesetList: function() {
      return this._changesetList;
    },

    /**
     * Has the content of this changeset been loaded?
     *
     * This method returns `true` if a request has been fired, even if the
     * response has not returned yet.
     *
     * @return bool True if the content has been loaded.
     */
    isLoaded: function() {
      return this._loaded;
    },


    /**
     * Configure stabilization of the document position on content load.
     *
     * When we dump the changeset into the document, we can try to stabilize
     * the document scroll position so that the user doesn't feel like they
     * are jumping around as things load in. This is generally useful when
     * populating initial changes.
     *
     * However, if a user explicitly requests a content load by clicking a
     * "Load" link or using the dropdown menu, this stabilization generally
     * feels unnatural, so we don't use it in response to explicit user action.
     *
     * @param bool  True to stabilize the next content fill.
     * @return this
     */
    setStabilize: function(stabilize) {
      this._stabilize = stabilize;
      return this;
    },


    /**
     * Should this changeset load immediately when the page loads?
     *
     * Normally, changes load immediately, but if a diff or commit is very
     * large we stop doing this and have the user load files explicitly, or
     * choose to load everything.
     *
     * @return bool True if the changeset should load automatically when the
     *   page loads.
     */
    shouldAutoload: function() {
      return this._getNodeData().autoload;
    },


    /**
     * Load this changeset, if it isn't already loading.
     *
     * This fires a request to fill the content of this changeset, provided
     * there isn't already a request in flight. To force a reload, use
     * @{method:reload}.
     *
     * @return this
     */
    load: function() {
      if (this._loaded) {
        return this;
      }

      return this.reload();
    },


    /**
     * Reload the changeset content.
     *
     * This method always issues a request, even if the content is already
     * loading. To load conditionally, use @{method:load}.
     *
     * @return this
     */
    reload: function(state) {
      this._loaded = true;
      this._sequence++;

      var workflow = this._newReloadWorkflow(state)
        .setHandler(JX.bind(this, this._onresponse, this._sequence));

      this._startContentWorkflow(workflow);

      var pht = this.getChangesetList().getTranslations();

      JX.DOM.setContent(
        this._getContentFrame(),
        JX.$N(
          'div',
          {className: 'differential-loading'},
          pht('Loading...')));

      return this;
    },

    _newReloadWorkflow: function(state) {
      var params = this._getViewParameters(state);
      return new JX.Workflow(this._renderURI, params);
    },

    /**
     * Load missing context in a changeset.
     *
     * We do this when the user clicks "Show X Lines". We also expand all of
     * the missing context when they "Show All Context".
     *
     * @param string Line range specification, like "0-40/0-20".
     * @param node Row where the context should be rendered after loading.
     * @param bool True if this is a bulk load of multiple context blocks.
     * @return this
     */
    loadContext: function(range, target, bulk) {
      var params = this._getViewParameters();
      params.range = range;

      var pht = this.getChangesetList().getTranslations();

      var container = JX.DOM.scry(target, 'td')[0];
      JX.DOM.setContent(container, pht('Loading...'));
      JX.DOM.alterClass(target, 'differential-show-more-loading', true);

      var workflow = new JX.Workflow(this._renderURI, params)
        .setHandler(JX.bind(this, this._oncontext, target));

      if (bulk) {
        // If we're loading a bunch of these because the viewer clicked
        // "Show All Context" or similar, use lower-priority requests
        // and draw a progress bar.
        this._startContentWorkflow(workflow);
      } else {
        // If this is a single click on a context link, use a higher priority
        // load without a chrome change.
        workflow.start();
      }

      return this;
    },

    loadAllContext: function() {
      var nodes = JX.DOM.scry(this._node, 'tr', 'context-target');
      for (var ii = 0; ii < nodes.length; ii++) {
        var show = JX.DOM.scry(nodes[ii], 'a', 'show-more');
        for (var jj = 0; jj < show.length; jj++) {
          var data = JX.Stratcom.getData(show[jj]);
          if (data.type != 'all') {
            continue;
          }
          this.loadContext(data.range, nodes[ii], true);
        }
      }
    },

    _startContentWorkflow: function(workflow) {
      var routable = workflow.getRoutable();

      routable
        .setPriority(500)
        .setType('content')
        .setKey(this._getRoutableKey());

      JX.Router.getInstance().queue(routable);
    },

    getDisplayPath: function() {
      return this._displayPath;
    },

    /**
     * Receive a response to a context request.
     */
    _oncontext: function(target, response) {
      // TODO: This should be better structured.
      // If the response comes back with several top-level nodes, the last one
      // is the actual context; the others are headers. Add any headers first,
      // then copy the new rows into the document.
      var markup = JX.$H(response.changeset).getFragment();
      var len = markup.childNodes.length;
      var diff = JX.DOM.findAbove(target, 'table', 'differential-diff');

      for (var ii = 0; ii < len - 1; ii++) {
        diff.parentNode.insertBefore(markup.firstChild, diff);
      }

      var table = markup.firstChild;
      var root = target.parentNode;
      this._moveRows(table, root, target);
      root.removeChild(target);

      this._onchangesetresponse(response);
    },

    _moveRows: function(src, dst, before) {
      var rows = JX.DOM.scry(src, 'tr');
      for (var ii = 0; ii < rows.length; ii++) {

        // Find the table this <tr /> belongs to. If it's a sub-table, like a
        // table in an inline comment, don't copy it.
        if (JX.DOM.findAbove(rows[ii], 'table') !== src) {
          continue;
        }

        if (before) {
          dst.insertBefore(rows[ii], before);
        } else {
          dst.appendChild(rows[ii]);
        }
      }
    },

    /**
     * Get parameters which define the current rendering options.
     */
    _getViewParameters: function(state) {
      var parameters = {
        ref: this._ref,
        device: this._getDefaultDeviceRenderer()
      };

      if (state) {
        JX.copy(parameters, state);
      }

      return parameters;
    },

    /**
     * Get the active @{class:JX.Routable} for this changeset.
     *
     * After issuing a request with @{method:load} or @{method:reload}, you
     * can adjust routable settings (like priority) by querying the routable
     * with this method. Note that there may not be a current routable.
     *
     * @return JX.Routable|null Active routable, if one exists.
     */
    getRoutable: function() {
      return JX.Router.getInstance().getRoutableByKey(this._getRoutableKey());
    },

    getRendererKey: function() {
      return this._rendererKey;
    },

    _getDefaultDeviceRenderer: function() {
      // NOTE: If you load the page at one device resolution and then resize to
      // a different one we don't re-render the diffs, because it's a
      // complicated mess and you could lose inline comments, cursor positions,
      // etc.
      return (JX.Device.getDevice() == 'desktop') ? '2up' : '1up';
    },

    getUndoTemplates: function() {
      return this._undoTemplates;
    },

    getCharacterEncoding: function() {
      return this._characterEncoding;
    },

    getHighlight: function() {
      return this._highlight;
    },

    getRequestDocumentEngineKey: function() {
      return this._requestDocumentEngineKey;
    },

    getResponseDocumentEngineKey: function() {
      return this._responseDocumentEngineKey;
    },

    getAvailableDocumentEngineKeys: function() {
      return this._availableDocumentEngineKeys;
    },

    getSelectableItems: function() {
      var items = [];

      items.push({
        type: 'file',
        changeset: this,
        target: this,
        nodes: {
          begin: this._node,
          end: null
        }
      });

      if (!this._visible) {
        return items;
      }

      var rows = JX.DOM.scry(this._node, 'tr');

      var blocks = [];
      var block;
      var ii;
      var parent_node = null;
      for (ii = 0; ii < rows.length; ii++) {
        var type = this._getRowType(rows[ii]);

        // This row might be part of a diff inside an inline comment, showing
        // an inline edit suggestion. Before we accept it as a possible target
        // for selection, make sure it's a child of the right parent.

        if (parent_node === null) {
          parent_node = rows[ii].parentNode;
        }

        if (type !== null) {
          if (rows[ii].parentNode !== parent_node) {
            type = null;
          }
        }

        if (!block || (block.type !== type)) {
          block = {
            type: type,
            items: []
          };
          blocks.push(block);
        }

        block.items.push(rows[ii]);
      }

      var last_inline = null;
      var last_inline_item = null;
      for (ii = 0; ii < blocks.length; ii++) {
        block = blocks[ii];

        if (block.type == 'change') {
          items.push({
            type: block.type,
            changeset: this,
            target: block.items[0],
            nodes: {
              begin: block.items[0],
              end: block.items[block.items.length - 1]
            }
          });
        }

        if (block.type == 'comment') {
          for (var jj = 0; jj < block.items.length; jj++) {
            var inline = this.getInlineForRow(block.items[jj]);

            // When comments are being edited, they have a hidden row with
            // the actual comment and then a visible row with the editor.

            // In this case, we only want to generate one item, but it should
            // use the editor as a scroll target. To accomplish this, check if
            // this row has the same inline as the previous row. If so, update
            // the last item to use this row's nodes.

            if (inline === last_inline) {
              last_inline_item.nodes.begin = block.items[jj];
              last_inline_item.nodes.end = block.items[jj];
              continue;
            } else {
              last_inline = inline;
            }

            var is_saved = (!inline.isDraft() && !inline.isEditing());

            last_inline_item = {
              type: block.type,
              changeset: this,
              target: inline,
              hidden: inline.isHidden(),
              collapsed: inline.isCollapsed(),
              deleted: !inline.getID() && !inline.isEditing(),
              nodes: {
                begin: block.items[jj],
                end: block.items[jj]
              },
              attributes: {
                unsaved: inline.isEditing(),
                anyDraft: inline.isDraft() || inline.isDraftDone(),
                undone: (is_saved && !inline.isDone()),
                done: (is_saved && inline.isDone())
              }
            };

            items.push(last_inline_item);
          }
        }
      }

      return items;
    },

    _getRowType: function(row) {
      // NOTE: Don't do "className.indexOf()" elsewhere. This is evil legacy
      // magic.

      if (row.className.indexOf('inline') !== -1) {
        return 'comment';
      }

      var cells = JX.DOM.scry(row, 'td');
      for (var ii = 0; ii < cells.length; ii++) {
        if (cells[ii].className.indexOf('old') !== -1 ||
            cells[ii].className.indexOf('new') !== -1) {
          return 'change';
        }
      }
    },

    _getNodeData: function() {
      return JX.Stratcom.getData(this._node);
    },

    getVectors: function() {
      return {
        pos: JX.$V(this._node),
        dim: JX.Vector.getDim(this._node)
      };
    },

    _onresponse: function(sequence, response) {
      if (sequence != this._sequence) {
        // If this isn't the most recent request, ignore it. This normally
        // means the user changed view settings between the time the page loaded
        // and the content filled.
        return;
      }

      // As we populate the changeset list, we try to hold the document scroll
      // position steady, so that, e.g., users who want to leave a comment on a
      // diff with a large number of changes don't constantly have the text
      // area scrolled off the bottom of the screen until the entire diff loads.
      //
      // There are several major cases here:
      //
      //  - If we're near the top of the document, never scroll.
      //  - If we're near the bottom of the document, always scroll, unless
      //    we have an anchor.
      //  - Otherwise, scroll if the changes were above (or, at least,
      //    almost entirely above) the viewport.
      //
      // We don't scroll if the changes were just near the top of the viewport
      // because this makes us scroll incorrectly when an anchored change is
      // visible. See T12779.

      var target = this._node;

      var old_pos = JX.Vector.getScroll();
      var old_view = JX.Vector.getViewport();
      var old_dim = JX.Vector.getDocument();

      // Number of pixels away from the top or bottom of the document which
      // count as "nearby".
      var sticky = 480;

      var near_top = (old_pos.y <= sticky);
      var near_bot = ((old_pos.y + old_view.y) >= (old_dim.y - sticky));

      // If we have an anchor in the URL, never stick to the bottom of the
      // page. See T11784 for discussion.
      if (window.location.hash) {
        near_bot = false;
      }

      var target_pos = JX.Vector.getPos(target);
      var target_dim = JX.Vector.getDim(target);
      var target_bot = (target_pos.y + target_dim.y);

      // Detect if the changeset is entirely (or, at least, almost entirely)
      // above us. The height here is roughly the height of the persistent
      // banner.
      var above_screen = (target_bot < old_pos.y + 64);

      // If we have a URL anchor and are currently nearby, stick to it
      // no matter what.
      var on_target = null;
      if (window.location.hash) {
        try {
          var anchor = JX.$(window.location.hash.replace('#', ''));
          if (anchor) {
            var anchor_pos = JX.$V(anchor);
            if ((anchor_pos.y > old_pos.y) &&
                (anchor_pos.y < old_pos.y + 96)) {
              on_target = anchor;
            }
          }
        } catch (ignored) {
          // If we have a bogus anchor, just ignore it.
        }
      }

      var frame = this._getContentFrame();
      JX.DOM.setContent(frame, JX.$H(response.changeset));

      if (this._stabilize) {
        if (on_target) {
          JX.DOM.scrollToPosition(old_pos.x, JX.$V(on_target).y - 60);
        } else if (!near_top) {
          if (near_bot || above_screen) {
            // Figure out how much taller the document got.
            var delta = (JX.Vector.getDocument().y - old_dim.y);
            JX.DOM.scrollToPosition(old_pos.x, old_pos.y + delta);
          }
        }
        this._stabilize = false;
      }

      this._onchangesetresponse(response);
    },

    _onchangesetresponse: function(response) {
      // Code shared by autoload and context responses.

      this._loadChangesetState(response);
      this._rebuildAllInlines();

      JX.Stratcom.invoke('resize');
    },

    _loadChangesetState: function(state) {
      if (state.coverage) {
        for (var k in state.coverage) {
          try {
            JX.DOM.replace(JX.$(k), JX.$H(state.coverage[k]));
          } catch (ignored) {
            // Not terribly important.
          }
        }
      }

      if (state.undoTemplates) {
        this._undoTemplates = state.undoTemplates;
      }

      this._rendererKey = state.rendererKey;
      this._highlight = state.highlight;
      this._characterEncoding = state.characterEncoding;
      this._requestDocumentEngineKey = state.requestDocumentEngineKey;
      this._responseDocumentEngineKey = state.responseDocumentEngineKey;
      this._availableDocumentEngineKeys = state.availableDocumentEngineKeys;
      this._isHidden = state.isHidden;

      var is_hidden = !this.isVisible();
      if (this._isHidden != is_hidden) {
        this.setVisible(!this._isHidden);
      }

      this._isLoading = false;
      this.getPathView().setIsLoading(this._isLoading);
    },

    _getContentFrame: function() {
      return JX.DOM.find(this._node, 'div', 'changeset-view-content');
    },

    _getRoutableKey: function() {
      return 'changeset-view.' + this._ref + '.' + this._sequence;
    },

    getInlineForRow: function(node) {
      var data = JX.Stratcom.getData(node);

      if (!data.inline) {
        var inline = this._newInlineForRow(node);
        this.getInlines().push(inline);
      }

      return data.inline;
    },

    _newInlineForRow: function(node) {
      return new JX.DiffInline()
        .setChangeset(this)
        .bindToRow(node);
    },

    newInlineForRange: function(origin, target, options) {
      var list = this.getChangesetList();

      var src = list.getLineNumberFromHeader(origin);
      var dst = list.getLineNumberFromHeader(target);

      var changeset_id = null;
      var side = list.getDisplaySideFromHeader(origin);
      if (side == 'right') {
        changeset_id = this.getRightChangesetID();
      } else {
        changeset_id = this.getLeftChangesetID();
      }

      var is_new = false;
      if (side == 'right') {
        is_new = true;
      } else if (this.getRightChangesetID() != this.getLeftChangesetID()) {
        is_new = true;
      }

      var data = {
        origin: origin,
        target: target,
        number: src,
        length: dst - src,
        changesetID: changeset_id,
        displaySide: side,
        isNewFile: is_new
      };

      JX.copy(data, options || {});

      var inline = new JX.DiffInline()
        .setChangeset(this)
        .bindToRange(data);

      this.getInlines().push(inline);

      inline.create();

      return inline;
    },

    newInlineReply: function(original, state) {
      var inline = new JX.DiffInline()
        .setChangeset(this)
        .bindToReply(original);

      this._inlines.push(inline);

      inline.create(state);

      return inline;
    },

    getInlineByID: function(id) {
      return this._queryInline('id', id);
    },

    getInlineByPHID: function(phid) {
      return this._queryInline('phid', phid);
    },

    _queryInline: function(field, value) {
      // First, look for the inline in the objects we've already built.
      var inline = this._findInline(field, value);
      if (inline) {
        return inline;
      }

      // If we haven't found a matching inline yet, rebuild all the inlines
      // present in the document, then look again.
      this._rebuildAllInlines();
      return this._findInline(field, value);
    },

    _findInline: function(field, value) {
      var inlines = this.getInlines();

      for (var ii = 0; ii < inlines.length; ii++) {
        var inline = inlines[ii];

        var target;
        switch (field) {
          case 'id':
            target = inline.getID();
            break;
          case 'phid':
            target = inline.getPHID();
            break;
        }

        if (target == value) {
          return inline;
        }
      }

      return null;
    },

    getInlines: function() {
      if (this._inlines === null) {
        this._rebuildAllInlines();
      }

      return this._inlines;
    },

    _rebuildAllInlines: function() {
      this._inlines = [];

      var rows = JX.DOM.scry(this._node, 'tr');
      var ii;
      for (ii = 0; ii < rows.length; ii++) {
        var row = rows[ii];
        if (this._getRowType(row) != 'comment') {
          continue;
        }

        this._inlines.push(this._newInlineForRow(row));
      }
    },

    redrawFileTree: function() {
      var inlines = this.getInlines();
      var done = [];
      var undone = [];
      var inline;

      for (var ii = 0; ii < inlines.length; ii++) {
        inline = inlines[ii];

        if (inline.isDeleted()) {
          continue;
        }

        if (inline.isUndo()) {
          continue;
        }

        if (inline.isSynthetic()) {
          continue;
        }

        if (inline.isEditing()) {
          continue;
        }

        if (!inline.getID()) {
          // These are new comments which have been cancelled, and do not
          // count as anything.
          continue;
        }

        if (inline.isDraft()) {
          continue;
        }

        if (!inline.isDone()) {
          undone.push(inline);
        } else {
          done.push(inline);
        }
      }

      var total = done.length + undone.length;

      var hint;
      var is_visible;
      var is_completed;
      if (total) {
        if (done.length) {
          hint = [done.length, '/', total];
        } else  {
          hint = total;
        }
        is_visible = true;
        is_completed = (done.length == total);
      } else {
        hint = '-';
        is_visible = false;
        is_completed = false;
      }

      var node = this.getPathView().getInlineNode();

      JX.DOM.setContent(node, hint);

      JX.DOM.alterClass(node, 'diff-tree-path-inlines-visible', is_visible);
      JX.DOM.alterClass(node, 'diff-tree-path-inlines-completed', is_completed);
    },

    _onClickHeader: function(e) {
      // If the user clicks the actual path name text, don't count this as
      // a selection action: we want to let them select the path.
      var path_name = e.getNode('changeset-header-path-name');
      if (path_name) {
        return;
      }

      // Don't allow repeatedly clicking a header to begin a "select word" or
      // "select line" operation.
      if (e.getType() === 'selectstart') {
        e.kill();
        return;
      }

      // NOTE: Don't prevent or kill the event. If the user has text selected,
      // clicking a header should clear the selection (and dismiss any inline
      // context menu, if one exists) as clicking elsewhere in the document
      // normally would.

      if (this._isSelected) {
        this.getChangesetList().selectChangeset(null);
      } else {
        this.select(false);
      }
    },

    toggleVisibility: function() {
      this.setVisible(!this._visible);

      var attrs = {
        hidden: this.isVisible() ? 0 : 1,
        discard: 1
      };

      var workflow = this._newReloadWorkflow(attrs)
        .setHandler(JX.bag);

      this._startContentWorkflow(workflow);
    },

    setVisible: function(visible) {
      this._visible = visible;

      var diff = this._getDiffNode();
      var options = this._getViewButtonNode();
      var show = this._getShowButtonNode();

      if (this._visible) {
        JX.DOM.show(diff);
        JX.DOM.show(options);
        JX.DOM.hide(show);
      } else {
        JX.DOM.hide(diff);
        JX.DOM.hide(options);
        JX.DOM.show(show);

        if (this._viewMenu) {
          this._viewMenu.close();
        }
      }

      JX.Stratcom.invoke('resize');

      var node = this._node;
      JX.DOM.alterClass(node, 'changeset-content-hidden', !this._visible);

      this.getPathView().setIsHidden(!this._visible);
    },

    setIsSelected: function(is_selected) {
      this._isSelected = !!is_selected;

      var node = this._node;
      JX.DOM.alterClass(node, 'changeset-selected', this._isSelected);

      return this;
    },

    _getDiffNode: function() {
      if (!this._diffNode) {
        this._diffNode = JX.DOM.find(this._node, 'table', 'differential-diff');
      }
      return this._diffNode;
    },

    _getViewButtonNode: function() {
      if (!this._viewButtonNode) {
        this._viewButtonNode = JX.DOM.find(
          this._node,
          'a',
          'differential-view-options');
      }
      return this._viewButtonNode;
    },

    _getShowButtonNode: function() {
      if (!this._showButtonNode) {
        var pht = this.getChangesetList().getTranslations();

        var show_button = new JX.PHUIXButtonView()
          .setIcon('fa-angle-double-down')
          .setText(pht('Show Changeset'))
          .setColor('grey');

        var button_node = show_button.getNode();
        this._getViewButtonNode().parentNode.appendChild(button_node);

        var onshow = JX.bind(this, this._onClickShowButton);
        JX.DOM.listen(button_node, 'click', null, onshow);

        this._showButtonNode = button_node;
      }
      return this._showButtonNode;
    },

    _onClickShowButton: function(e) {
      e.prevent();

      // We're always showing the changeset, but want to make sure the state
      // change is persisted on the server.
      this.toggleVisibility();
    },

    isVisible: function() {
      return this._visible;
    },

    getPathView: function() {
      if (!this._pathView) {
        var view = new JX.DiffPathView()
          .setChangeset(this)
          .setPath(this._pathParts)
          .setIsLowImportance(this._isLowImportance)
          .setIsOwned(this._isOwned)
          .setIsLoading(this._isLoading);

        view.getIcon()
          .setIcon(this._pathIconIcon)
          .setColor(this._pathIconColor);

        this._pathView = view;
      }

      return this._pathView;
    },

    select: function(scroll) {
      this.getChangesetList().selectChangeset(this, scroll);
      return this;
    }
  },

  statics: {
    getForNode: function(node) {
      var data = JX.Stratcom.getData(node);
      if (!data.changesetViewManager) {
        data.changesetViewManager = new JX.DiffChangeset(node);
      }
      return data.changesetViewManager;
    }
  }
});