The GWindow

The GWindow is an HTML5 Canvas that you can use other JSGraphics library functions with. Greatly simplifies the process of working with Canvases.

Meant to mimic the graphics libraries from CS106A's Java curriculum.

Factory Functions

function GWindow()

function GWindow(id)

function GWindow(width, height)

function GWindow(id, width, height)

Creates a new GWindow object with a given width/height, and displays it in the given HTML element id.

If width or height is unspecified, it will default to 0, 0 (or whatever value is defined in CSS).

If id is unspecified, it will default to an element with id JSConsole or the body of the document.

Returns: A new GWindow instance.

Methods

function GWindow::addEventListener(eventType, listener)

Stores an event listener in this GWindow. When the GWindow receives an event of the given eventType, it invokes the listener function.

eventType should be a string. listener should be a function that takes no arguments.

The following event types are valid:

Event Type	Description
click	Invoked when a user finishes clicking, but not dragging, the GWindow.
dblclick	Invoked when a user double-clicks the GWindow.
mousedown	Invoked when a user's mouse clicks down on the GWindow.
mouseup	Invoked when a user's mouse button releases on the GWindow.
drag	Invoked when a user is holding down their mouse button, and moving their mouse.
mousemove	Invoked whenever the user moves their cursor.
keydown	Invoked whenever a user clicks a keyboard key

function GWindow::add(gObject[, x, y])

Adds the specified gObject to the window at the location previously stored in the object. x and y are optional; if they are supplied, then gObject is moved to the specified location.

function GWindow::remove(gObject)

Removes the specified gObject from the window. If the object wasn't added to the window, this method has no effect.

function GWindow::clear()

Removes all GObjects from the window.

Alias: GWindow::removeAll()

function GWindow::setSize(width, height)

Sets the dimensions of the window as specified.

function GWindow::getElementCount()

Returns: The number of elements contained in the window.

function GWindow::getElement(index)

Returns: The GObject at the specified index (where index 0 was the first GObject added to the window/the GObject farthest back, and the last index is the most recently added/most on top GObject).

function GWindow::getElementAt(x, y)

Gets the topmost (i.e. most recently-added) GObject at the specified x/y coordinates.

Returns: The found GObject, or null if there's not an object at the specified coordinates.

function GWindow::setAutoRepaintFlag(flag)

Changes the setting of the auto-repaint flag. By default, any change to a graphical object contained in this window automatically triggers a repaint of the window as a whole. While this behavior makes it easier to use JSGraphics, it has the disadvantage that repaint requests come much more frequently than necessary. You can disable this feature by calling gwindowObj.setAutoRepaintFlag(false), but you must then make explicit calls to gwindowObj.repaint() whenever you want to update the display. The advantage of this model is that you can then make many different changes and have them all appear at once with a single repaint call.

function GWindow::getAutoRepaintFlag()

Returns: true if the window is set to always auto-repaint, false otherwise.

function GWindow::repaint()

Forces the window to repaint itself immediately.

function GWindow::getSize()

Returns: The width and height of the window as a GDimension.

function GWindow::getWidth()

Returns: The width of the window as a number.

function GWindow::getHeight()

Returns: The height of the window as a number.

function GWindow::setScaleFactor(multiplier)

Scales the entire window by the a multiplier. The window's scale factor is 1 by default.

function GWindow::getScaleFactor()

Returns: The scale factor of the window.