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Terms, Icons, and Labels

Many classes have shortcut names used when creating (instantiating) a class with a configuration object. The shortcut name is referred to as an alias (or xtype if the class extends Ext.Component). The alias/xtype is listed next to the class name of applicable classes for quick reference.

Access Levels

Framework classes or their members may be specified as private or protected. Else, the class / member is public. Public, protected, and private are access descriptors used to convey how and when the class or class member should be used.

Member Types

Member Syntax

Below is an example class member that we can disect to show the syntax of a class member (the lookupComponent method as viewed from the Ext.button.Button class in this case).

lookupComponent ( item ) : Ext.Component

Called when a raw config object is added to this container either during initialization of the items config, or when new items are added), or {@link #insert inserted.

This method converts the passed object into an instanced child component.

This may be overridden in subclasses when special processing needs to be applied to child creation.


item :  Object

The config object being added.


The component to be added.

Let's look at each part of the member row:

Member Flags

The API documentation uses a number of flags to further commnicate the class member's function and intent. The label may be represented by a text label, an abbreviation, or an icon.

Class Icons

- Indicates a framework class

- A singleton framework class. *See the singleton flag for more information

- A component-type framework class (any class within the Ext JS framework that extends Ext.Component)

- Indicates that the class, member, or guide is new in the currently viewed version

Member Icons

- Indicates a class member of type config

- Indicates a class member of type property

- Indicates a class member of type method

- Indicates a class member of type event

- Indicates a class member of type theme variable

- Indicates a class member of type theme mixin

- Indicates that the class, member, or guide is new in the currently viewed version

Class Member Quick-Nav Menu

Just below the class name on an API doc page is a row of buttons corresponding to the types of members owned by the current class. Each button shows a count of members by type (this count is updated as filters are applied). Clicking the button will navigate you to that member section. Hovering over the member-type button will reveal a popup menu of all members of that type for quick navigation.

Getter and Setter Methods

Getting and setter methods that correlate to a class config option will show up in the methods section as well as in the configs section of both the API doc and the member-type menus just beneath the config they work with. The getter and setter method documentation will be found in the config row for easy reference.

History Bar

Your page history is kept in localstorage and displayed (using the available real estate) just below the top title bar. By default, the only search results shown are the pages matching the product / version you're currently viewing. You can expand what is displayed by clicking on the button on the right-hand side of the history bar and choosing the "All" radio option. This will show all recent pages in the history bar for all products / versions.

Within the history config menu you will also see a listing of your recent page visits. The results are filtered by the "Current Product / Version" and "All" radio options. Clicking on the button will clear the history bar as well as the history kept in local storage.

If "All" is selected in the history config menu the checkbox option for "Show product details in the history bar" will be enabled. When checked, the product/version for each historic page will show alongside the page name in the history bar. Hovering the cursor over the page names in the history bar will also show the product/version as a tooltip.

Search and Filters

Both API docs and guides can be searched for using the search field at the top of the page.

On API doc pages there is also a filter input field that filters the member rows using the filter string. In addition to filtering by string you can filter the class members by access level, inheritance, and read only. This is done using the checkboxes at the top of the page.

The checkbox at the bottom of the API class navigation tree filters the class list to include or exclude private classes.

Clicking on an empty search field will show your last 10 searches for quick navigation.

API Doc Class Metadata

Each API doc page (with the exception of Javascript primitives pages) has a menu view of metadata relating to that class. This metadata view will have one or more of the following:

Expanding and Collapsing Examples and Class Members

Runnable examples (Fiddles) are expanded on a page by default. You can collapse and expand example code blocks individually using the arrow on the top-left of the code block. You can also toggle the collapse state of all examples using the toggle button on the top-right of the page. The toggle-all state will be remembered between page loads.

Class members are collapsed on a page by default. You can expand and collapse members using the arrow icon on the left of the member row or globally using the expand / collapse all toggle button top-right.

Desktop -vs- Mobile View

Viewing the docs on narrower screens or browsers will result in a view optimized for a smaller form factor. The primary differences between the desktop and "mobile" view are:

Viewing the Class Source

The class source can be viewed by clicking on the class name at the top of an API doc page. The source for class members can be viewed by clicking on the "view source" link on the right-hand side of the member row.

GXT 4.x


Getting Started with Touch Development

GXT 4 introduces touch support for tablet devices. This guide covers getting started with touch features in GXT 4.

Setting the Viewport

When running a GXT application on a tablet, some touch interactions may conflict with system gestures. For example, if your application uses widgets that respond to a double tap gesture, it may conflict with the system double-tap-to-zoom feature. One solution is to "lock" the viewport so that the user cannot use the system zoom feature. To do this, add a viewport meta tag to the application's host page (index.html) as follows:

    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">

This viewport meta tag will prevent zooming altogether. However, many applications that were originally designed for desktop will appear crowded on smaller on tablet screens. Ideally, you should create a tablet UI with touch targets designed specifically for tablet devices and disable system gestures in order to prevent gesture conflicts. However, a possible compromise is to restrict zooming but not to disable it altogether. To do that, you can use a meta tag such as this, which allows pinch-to-zoom up to 3x:

    <meta name="viewport" content="width=device-width, initial-scale=1, 
    maximum-scale=3, user-scalable=yes">

Incorporating Touch Features

There are three primary ways to include touch features in your app. These are explained in the sections below.

Use Touch-Enabled Widgets

In GXT 4, interactive widgets have been enhanced to respond to touch. In most cases, you will not have to update your code to take advantage of the new touch features. For example, buttons like com.sencha.gxt.widget.core.client.button.TextButton already handle com.sencha.gxt.widget.core.client.event.SelectEvent, which fires in response to a mouse click or touch. Similarly, the com.sencha.gxt.widget.core.client.tree.Tree will automatically respond to touch events to collapse and expand nodes. Many widgets that now handle touch events simply delegate to the appropriate click handler (onMouseClick, onMouseDown, etc.) so if you've already implemented functionality in these methods, you likely won't have to change your code at all. However, in some cases you may want to respond to touch events specifically. In the next section, we'll look at how to do this using GestureRecognizers.

Use GestureRecognizers

GXT touch support is implemented using com.sencha.gxt.core.client.gestures.GestureRecognizers which convert touch events into logical gestures such as tap, double-tap, and long press. In GXT 4, many widgets and cells have already added GestureRecognizers to handle typical touch events. In addition, you can easily add a GestureRecognizer to any Widget or Cell.

For example, suppose you have a custom Cell that you want to handle a tap in a specific way. To do this, extend com.sencha.gxt.cell.core.client.AbstractEventCell and put the following in the constructor:

addCellGestureAdapter(new TapGestureRecognizer.CellTapGestureRecognizer<C>() {
    protected void onTap(TouchData tap, Context context, Element parent, C value, ValueUpdater<C> valueUpdater) {

Refer to the Gestures guide for a list of the available gesture recognizers along with more explanation and examples.

Listen for Gesture Events

Each com.sencha.gxt.core.client.gestures.GestureRecognizer defines logical events such as $TapGestureEvent and $LongPressEvent . By default, a GestureRecognizer fires its events to the Component, Cell, or Widget which registered it (you can supply a different handler by calling the com.sencha.gxt.core.client.gestures.GestureRecognizer's setDelegate method after the call to addGestureRecognizer()). Therefore, another method of acting on gesture-related events is to add a handler for them using

For example, com.sencha.gxt.widget.core.client.TabPanel registers a TapGestureRecognizer. If you want to get notified of any TapGestureEvent on the panel, you can add a handler to it like this:

tabPanel.addHandler(new TapGestureRecognizer.TapGestureEvent.TapGestureHandler {
    void onTapGesture(TapGestureEvent event) {
        // do something
}, TapGestureRecognizer.TapGestureEvent.getType());

Using the gxt.device Property

GXT 4 introduces a new property gxt.device which creates specific permutations for desktop vs. tablet devices. Currently, the detection logic is very simple. If the user agent is a recognized mobile OS (Android, iPad/iPod/iPhone, BlackBerry, IEMobile), the gxt.device property will have the value tablet. Otherwise, it will have the value desktop. GXT does not yet support phones since GXT widgets weren't designed for the typically smaller screens. However, phone is a valid value of the gxt.device property for purposes of future compatibility.

By default, the new gxt.device property will result in more GWT permutations being built when you compile your application. To avoid this, it is recommended to put the following directive in your '*.gwt.xml' file:

    <collapse-property name="gxt.device" values="*" />

Find out more about collapsing properties in the Permutations guide.

In addition, you can access the gxt.device property at runtime via methods on the com.sencha.gxt.core.client.GXT class. These are

  • boolean GXT.isDesktop()
  • boolean GXT.isTablet()

GXT 4.x