Improve right sidebar tabs behavior

Tab heads are not rendered if only one tab.

The tab contents is updated on-demand. This means that if a tab is not
visible it is not rendered at first. If the tab was already rendered
through switching, its model will not get updated until the next time it
becomes visible. This will prevent needless rerendering of invisible tab
contents, especially considering that some tabs might need extra ajax
requests.

1 files changed, 112 insertions, 64 deletions

diff --git a/apps/files/js/detailsview.js b/apps/files/js/detailsview.js
index 4df359e4523..a4ebe90cd64 100644
--- a/apps/files/js/detailsview.js
+++ b/apps/files/js/detailsview.js
@@ -9,23 +9,26 @@
  */
 
 (function() {
-
 	var TEMPLATE =
 		'<div>' +
-		'    <div class="detailFileInfoContainer">' +
-		'    </div>' +
-		'    <div>' +
-		'        <ul class="tabHeaders">' +
-		'        </ul>' +
-		'        <div class="tabsContainer">' +
-		'        </div>' +
-		'    </div>' +
-		'    <a class="close icon-close" href="#" alt="{{closeLabel}}"></a>' +
+		'	<div class="detailFileInfoContainer">' +
+		'	</div>' +
+		'	<div>' +
+		'		{{#if tabHeaders}}' +
+		'		<ul class="tabHeaders">' +
+		'		{{#each tabHeaders}}' +
+		'		<li class="tabHeader" data-tabid="{{tabId}}" data-tabindex="{{tabIndex}}">' +
+		'			<a href="#">{{label}}</a>' +
+		'		</li>' +
+		'		{{/each}}' +
+		'		</ul>' +
+		'		{{/if}}' +
+		'		<div class="tabsContainer">' +
+		'		</div>' +
+		'	</div>' +
+		'	<a class="close icon-close" href="#" alt="{{closeLabel}}"></a>' +
 		'</div>';
 
-	var TEMPLATE_TAB_HEADER =
-		'<li class="tabHeader {{#if selected}}selected{{/if}}" data-tabid="{{tabId}}" data-tabindex="{{tabIndex}}"><a href="#">{{label}}</a></li>';
-
 	/**
 	 * @class OCA.Files.DetailsView
 	 * @classdesc
@@ -39,7 +42,6 @@
 		className: 'detailsView',
 
 		_template: null,
-		_templateTabHeader: null,
 
 		/**
 		 * List of detail tab views
@@ -62,6 +64,11 @@
 		 */
 		_currentTabId: null,
 
+		/**
+		 * Dirty flag, whether the view needs to be rerendered
+		 */
+		_dirty: false,
+
 		events: {
 			'click a.close': '_onClose',
 			'click .tabHeaders .tabHeader': '_onClickTab'
@@ -74,8 +81,10 @@
 			this._tabViews = [];
 			this._detailFileInfoViews = [];
 
+			this._dirty = true;
+
 			// uncomment to add some dummy tabs for testing
-			// this._addTestTabs();
+			//this._addTestTabs();
 		},
 
 		_onClose: function(event) {
@@ -85,28 +94,21 @@
 
 		_onClickTab: function(e) {
 			var $target = $(e.target);
+			e.preventDefault();
 			if (!$target.hasClass('tabHeader')) {
 				$target = $target.closest('.tabHeader');
 			}
-			var tabIndex = $target.attr('data-tabindex');
-			var targetTab;
-			if (_.isUndefined(tabIndex)) {
+			var tabId = $target.attr('data-tabid');
+			if (_.isUndefined(tabId)) {
 				return;
 			}
 
-			this.$el.find('.tabsContainer .tab').addClass('hidden');
-			targetTab = this._tabViews[tabIndex];
-			targetTab.$el.removeClass('hidden');
-
-			this.$el.find('.tabHeaders li').removeClass('selected');
-			$target.addClass('selected');
-
-			e.preventDefault();
+			this.selectTab(tabId);
 		},
 
 		_addTestTabs: function() {
 			for (var j = 0; j < 2; j++) {
-				var testView = new OCA.Files.DetailTabView('testtab' + j);
+				var testView = new OCA.Files.DetailTabView({id: 'testtab' + j});
 				testView.index = j;
 				testView.getLabel = function() { return 'Test tab ' + this.index; };
 				testView.render = function() {
@@ -119,26 +121,34 @@
 			}
 		},
 
+		template: function(vars) {
+			if (!this._template) {
+				this._template = Handlebars.compile(TEMPLATE);
+			}
+			return this._template(vars);
+		},
+
 		/**
 		 * Renders this details view
 		 */
 		render: function() {
-			var self = this;
-
-			if (!this._template) {
-				this._template = Handlebars.compile(TEMPLATE);
-			}
+			var templateVars = {
+				closeLabel: t('files', 'Close')
+			};
 
-			if (!this._templateTabHeader) {
-				this._templateTabHeader = Handlebars.compile(TEMPLATE_TAB_HEADER);
+			if (this._tabViews.length > 1) {
+				// only render headers if there is more than one available
+				templateVars.tabHeaders = _.map(this._tabViews, function(tabView, i) {
+					return {
+						tabId: tabView.id,
+						tabIndex: i,
+						label: tabView.getLabel()
+					};
+				});
 			}
 
-			this.$el.html(this._template({
-				closeLabel: t('files', 'Close')
-			}));
+			this.$el.html(this.template(templateVars));
 
-			var $tabsContainer = this.$el.find('.tabsContainer');
-			var $tabHeadsContainer = this.$el.find('.tabHeaders');
 			var $detailsContainer = this.$el.find('.detailFileInfoContainer');
 
 			// render details
@@ -146,29 +156,58 @@
 				$detailsContainer.append(detailView.get$());
 			});
 
-			if (this._tabViews.length > 0) {
-				if (!this._currentTab) {
-					this._currentTab = this._tabViews[0].id;
-				}
-
-				// render tabs
-				_.each(this._tabViews, function(tabView, i) {
-					// hidden by default
-					var $el = tabView.get$();
-					var isCurrent = (tabView.id === self._currentTab);
-					if (!isCurrent) {
-						$el.addClass('hidden');
-					}
-					$tabsContainer.append($el);
+			if (!this._currentTabId && this._tabViews.length > 0) {
+				this._currentTabId = this._tabViews[0].id;
+			}
 
-					$tabHeadsContainer.append(self._templateTabHeader({
-						tabId: tabView.id,
-						tabIndex: i,
-						label: tabView.getLabel(),
-						selected: isCurrent
-					}));
-				});
+			this.selectTab(this._currentTabId);
+
+			this._dirty = false;
+		},
+
+		/**
+		 * Selects the given tab by id
+		 *
+		 * @param {string} tabId tab id
+		 */
+		selectTab: function(tabId) {
+			if (!tabId) {
+				return;
+			}
+
+			var tabView = _.find(this._tabViews, function(tab) {
+				return tab.id === tabId;
+			});
+
+			if (!tabView) {
+				console.warn('Details view tab with id "' + tabId + '" not found');
+				return;
 			}
+
+			this._currentTabId = tabId;
+
+			var $tabsContainer = this.$el.find('.tabsContainer');
+			var $tabEl = $tabsContainer.find('#' + tabId);
+
+			// hide other tabs
+			$tabsContainer.find('.tab').addClass('hidden');
+
+			// tab already rendered ?
+			if (!$tabEl.length) {
+				// render tab
+				$tabsContainer.append(tabView.$el);
+				$tabEl = tabView.$el;
+			}
+
+			// this should trigger tab rendering
+			tabView.setFileInfo(this.model);
+
+			$tabEl.removeClass('hidden');
+
+			// update tab headers
+			var $tabHeaders = this.$el.find('.tabHeaders li');
+			$tabHeaders.removeClass('selected');
+			$tabHeaders.filterAttr('data-tabid', tabView.id).addClass('selected');
 		},
 
 		/**
@@ -179,12 +218,19 @@
 		setFileInfo: function(fileInfo) {
 			this.model = fileInfo;
 
-			this.render();
+			if (this._dirty) {
+				this.render();
+			}
 
-			// notify all panels
-			_.each(this._tabViews, function(tabView) {
+			if (this._currentTabId) {
+				// only update current tab, others will be updated on-demand
+				var tabId = this._currentTabId;
+				var tabView = _.find(this._tabViews, function(tab) {
+					return tab.id === tabId;
+				});
 				tabView.setFileInfo(fileInfo);
-			});
+			}
+
 			_.each(this._detailFileInfoViews, function(detailView) {
 				detailView.setFileInfo(fileInfo);
 			});
@@ -206,6 +252,7 @@
 		 */
 		addTabView: function(tabView) {
 			this._tabViews.push(tabView);
+			this._dirty = true;
 		},
 
 		/**
@@ -215,6 +262,7 @@
 		 */
 		addDetailView: function(detailView) {
 			this._detailFileInfoViews.push(detailView);
+			this._dirty = true;
 		}
 	});