goog.graphics.CanvasGraphics

Adds the specified component as the last child of this component. See goog.ui.Component#addChildAt for detailed semantics.

Adds the specified component as a child of this component at the given 0-based index.

Both addChild and addChildAt assume the following contract between parent and child components:

• the child component's element must be a descendant of the parent component's element, and
• the DOM state of the child component must be consistent with the DOM state of the parent component (see `isInDocument`) in the steady state -- the exception is to addChildAt(child, i, false) and then immediately decorate/render the child.

In particular, parent.addChild(child) will throw an error if the child component is already in the document, but the parent isn't.

Clients of this API may call addChild and addChildAt with opt_render set to true. If opt_render is true, calling these methods will automatically render the child component's element into the parent component's element. If the parent does not yet have an element, then createDom will automatically be invoked on the parent before rendering the child.

Invoking parent.addChild(child, true) will throw an error if the child component is already in the document, regardless of the parent's DOM state.

If opt_render is true and the parent component is not already in the document, enterDocument will not be called on this component at this point.

Finally, this method also throws an error if the new child already has a different parent, or the given index is out of bounds.

Adds an event listener to the event target. The same handler can only be added once per the type. Even if you add the same handler multiple times using the same type then it will only be called once when the event is dispatched.

Invokes a callback function when this object is disposed. Callbacks are invoked in the order in which they were added. If a callback is added to an already disposed Disposable, it will be called immediately.

Append an element.

Determines if a given element can be decorated by this type of component. This method should be overridden by inheriting objects.

Remove all drawing elements from the graphics.

Creates the DOM representation of the graphics area.

Create an empty group of drawing elements.

Create an empty path.

Decorates the element for the UI component. If the element is in the document, the enterDocument method will be called.

If goog.ui.Component.ALLOW_DETACHED_DECORATION is false, the caller must pass an element that is in the document.

Actually decorates the element. Should be overridden by inheriting objects. This method can assume there are checks to ensure the component has not already been rendered have occurred and that enter document will be called afterwards. This method is considered protected.

Dispatches an event (or event like object) and calls all listeners listening for events of this type. The type of the event is decided by the type property on the event object.

If any of the listeners returns false OR calls preventDefault then this function will return false. If one of the capture listeners calls stopPropagation, then the bubble listeners won't fire.

Disposes of the object and its resources.

Disposes of the component by removing event handlers, detacing DOM nodes from the document body, and removing references to them.

Draw a circle

Draw an element, including any stroke or fill.

Draw an ellipse.

Draw an image.

Draw a path.

Draw a rectangle.

Draw a text string within a rectangle (drawing is horizontal)

Draw a text string vertically centered on a given line.

Called when the component's element is known to be in the document. Anything using document.getElementById etc. should be done at this stage.

If the component contains child components, this call is propagated to its children.

Called by dispose to clean up the elements and listeners created by a component, or by a parent component/application who has removed the component from the document but wants to reuse it later.

If the component contains child components, this call is propagated to its children.

It should be possible for the component to be rendered again once this method has been called.

Fires all registered listeners in this listenable for the given type and capture mode, passing them the given eventObject. This does not perform actual capture/bubble. Only implementors of the interface should be using this.

Calls the given function on each of this component's children in order. If opt_obj is provided, it will be used as the 'this' object in the function when called. The function should take two arguments: the child component and its 0-based index. The return value is ignored.

Returns the child with the given ID, or null if no such child exists.

Returns the child at the given index, or null if the index is out of bounds.

Returns the number of children of this component.

Returns an array containing the IDs of the children of this component, or an empty array if the component has no children.

Returns the DOM element into which child components are to be rendered, or null if the component itself hasn't been rendered yet. This default implementation returns the component's root element. Subclasses with complex DOM structures must override this method.

Returns the drawing context.

Returns the dom helper that is being used on this component.

Gets the component's element.

Returns the first element in this component's DOM with the provided className.

Helper function for returning an element in the document with a unique id generated using makeId().

Gets the component's element. This differs from getElement in that it assumes that the element exists (i.e. the component has been rendered/decorated) and will cause an assertion error otherwise (if assertion is enabled).

Returns an array of all the elements in this component's DOM with the provided className.

Helper function for returning the fragment portion of an id generated using makeId().

Returns the event handler for this component, lazily created the first time this method is called.

Gets the unique ID for the instance of this component. If the instance doesn't already have an ID, generates one on the fly.

Gets the goog.events.ListenableKey for the event or null if no such listener is in use.

Gets all listeners in this listenable for the given type and capture mode.

Returns the model associated with the UI component.

Returns the component's parent, if any.

Returns the parent of this event target to use for capture/bubble mechanism.

NOTE(chrishenry): The name reflects the original implementation of custom event target (goog.events.EventTarget). We decided that changing the name is not worth it.

Similar to getElementByClass except that it expects the element to be present in the dom thus returning a required value. Otherwise, will assert.

Measure and return the width (in pixels) of a given text string. Text measurement is needed to make sure a text can fit in the allocated area. The way text length is measured is by writing it into a div that is after the visible area, measure the div width, and immediately erase the written value.

Returns true if the component has children.

Whether there is any active listeners matching the specified signature. If either the type or capture parameters are unspecified, the function will match on the remaining criteria.

Returns the 0-based index of the given child component, or -1 if no such child is found.

Determines whether the component has been added to the document.

Returns true if drawing to the given group means a redraw is required.

Returns true if the component is rendered right-to-left, false otherwise. The first time this function is invoked, the right-to-left rendering property is set if it has not been already.

Adds an event listener. A listener can only be added once to an object and if it is added again the key for the listener is returned. Note that if the existing listener is a one-off listener (registered via listenOnce), it will no longer be a one-off listener after a call to listen().

Adds an event listener that is removed automatically after the listener fired once.

If an existing listener already exists, listenOnce will do nothing. In particular, if the listener was previously registered via listen(), listenOnce() will not turn the listener into a one-off listener. Similarly, if there is already an existing one-off listener, listenOnce does not modify the listeners (it is still a once listener).

Helper function for subclasses that gets a unique id for a given fragment, this can be used by components to generate unique string ids for DOM elements.

Makes a collection of ids. This is a convenience method for makeId. The object's values are the id fragments and the new values are the generated ids. The key will remain the same.

Returns whether this component should listen for PointerEvent types rather than MouseEvent types. This allows supporting drag gestures for touch/stylus input.

Pop an element transform off of the transform stack.

Push an element transform on to the transform stack.

Redraw the entire canvas.

Associates a disposable object with this object so that they will be disposed together.

Removes all listeners from this listenable. If type is specified, it will only remove listeners of the particular type. otherwise all registered listeners will be removed.

Removes the given child from this component, and returns it. Throws an error if the argument is invalid or if the specified child isn't found in the parent component. The argument can either be a string (interpreted as the ID of the child component to remove) or the child component itself.

If opt_unrender is true, calls goog.ui.component#exitDocument on the removed child, and subsequently detaches the child's DOM from the document. Otherwise it is the caller's responsibility to clean up the child component's DOM.

Removes the child at the given index from this component, and returns it. Throws an error if the argument is out of bounds, or if the specified child isn't found in the parent. See goog.ui.Component#removeChild for detailed semantics.

Removes every child component attached to this one and returns them.

Removes an element from the Canvas.

Removes an event listener from the event target. The handler must be the same object as the one added. If the handler has not been added then nothing is done.

Renders the component. If a parent element is supplied, the component's element will be appended to it. If there is no optional parent element and the element doesn't have a parentNode then it will be appended to the document body.

If this component has a parent component, and the parent component is not in the document already, then this will not call enterDocument on this component.

Throws an Error if the component is already rendered.

Renders the component before another element. The other element should be in the document already.

Throws an Error if the component is already rendered.

Reset the canvas.

Stop preventing redraws. If any redraws had been prevented, a redraw will be done now.

Changes the coordinate system position.

Changes the coordinate size.

Set the transformation of an element.

Note that in this implementation this method just calls this.redraw() and the affineTransform param is unused.

Sets the fill for the given element.

Sets the component's root element to the given element. Considered protected and final.

This should generally only be called during createDom. Setting the element does not actually change which element is rendered, only the element that is associated with this UI component.

This should only be used by subclasses and its associated renderers.

Sets the stroke for the given element.

Set the translation and rotation of an element.

If a more general affine transform is needed than this provides (e.g. skew and scale) then use setElementAffineTransform.

Assigns an ID to this component instance. It is the caller's responsibility to guarantee that the ID is unique. If the component is a child of a parent component, then the parent component's child index is updated to reflect the new ID; this may throw an error if the parent already has a child with an ID that conflicts with the new ID.

Sets the model associated with the UI component.

Sets the parent of this component to use for event bubbling. Throws an error if the component already has a parent or if an attempt is made to add a component to itself as a child. Callers must use removeChild or removeChildAt to remove components from their containers before calling this method.

Overrides goog.events.EventTarget#setParentEventTarget to throw an error if the parent component is set, and the argument is not the parent.

Indicates whether this component should listen for PointerEvent types rather than MouseEvent types. This allows supporting drag gestures for touch/stylus input. Must be called before enterDocument to listen for the correct event types.

Set is right-to-left. This function should be used if the component needs to know the rendering direction during dom creation (i.e. before #enterDocument is called and is right-to-left is set).

Change the size of the canvas.

Sets the target to be used for event.target when firing event. Mainly used for testing. For example, see goog.testing.events.mixinListenable.

Start preventing redraws - useful for chaining large numbers of changes together. Not guaranteed to do anything - i.e. only use this for optimization of a single code path.

Removes an event listener which was added with listen() or listenOnce().

Removes an event listener which was added with listen() by the key returned by listen().

Update the size of the canvas.

The main canvas element.

Height of coordinate system in units.

Left coordinate of the view box

Top coordinate of the view box

Width of coordinate system in units.

If monitoring the goog.Disposable instances is enabled, stores the creation stack trace of the Disposable instance.

DomHelper used to interact with the document, allowing components to be created in a different window.

Height of graphics in pixels or percentage points.

Width of graphics in pixels or percentage points.