Package nl.colorize.multimedialib.renderer

Class Canvas

java.lang.Object

nl.colorize.multimedialib.renderer.Canvas

public class Canvas
extends java.lang.Object

Represents the resolution of the application graphics independently from the device's screen resolution. The canvas is initially created with a preferred width and height. When the screen or window is resized, the canvas will also be resized while keeping its original aspect ratio.

Having a consistent canvas size across different devices ensures a consistent user experience in situations where the same application is used across a variety of devices with different screen sizes. This class is then used to translate between the two coordinate systems.

Alternatively, a flexible canvas can be created. In this case, the canvas follows the screen resolution without considering the requested width/height or aspect ratio.

Method Summary

Modifier and Type	Method	Description
static Canvas	fixed(int preferredWidth, int preferredHeight)	Creates a canvas with fixed dimensions.
static Canvas	flexible(int initialWidth, int initialHeight)	Creates a canvas that resizes itself to match the screen size, always keeping a zoom level of 1.0.
Rect	getBounds()
Point	getCenter()
int	getHeight()
int	getWidth()
float	getZoomLevel()
void	offsetScreen(int offsetX, int offsetY)	Offset the canvas position on the screen.
void	resizeScreen(int screenWidth, int screenHeight)	Sets the screen dimensions to the specified values.
static Canvas	responsive(int initialWidth, int initialHeight, float minZoom, float maxZoom)	Creates a canvas that resizes itself to match the screen size, as long as the zoom level stays within the specified bounds.
float	toCanvasX(int screenX)
float	toCanvasY(int screenY)
float	toScreenX(float canvasX)
float	toScreenY(float canvasY)
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

resizeScreen

public void resizeScreen(int screenWidth,
                         int screenHeight)

Sets the screen dimensions to the specified values. This method should be called by the renderer when the application window is first created, and whenever the window is resized.

offsetScreen

public void offsetScreen(int offsetX,
                         int offsetY)

Offset the canvas position on the screen. This is mainly needed for when the screen contains system UI such as a status bar or window title where no application graphics can be displayed.

getWidth

public int getWidth()

getHeight

public int getHeight()

getBounds

public Rect getBounds()

getCenter

public Point getCenter()

getZoomLevel

public float getZoomLevel()

toCanvasX

public float toCanvasX(int screenX)

toCanvasY

public float toCanvasY(int screenY)

toScreenX

public float toScreenX(float canvasX)

toScreenY

public float toScreenY(float canvasY)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

fixed

public static Canvas fixed(int preferredWidth,
                           int preferredHeight)

Creates a canvas with fixed dimensions. The canvas will be scaled to match the current screen size. Note that it might not be possible to retain the preferred canvas dimensions in all cases, as the screen might have a different aspect ratio than the canvas.

flexible

public static Canvas flexible(int initialWidth,
                              int initialHeight)

Creates a canvas that resizes itself to match the screen size, always keeping a zoom level of 1.0. The provided width and height are only used to initialize the canvas but will not be used afterwards.

responsive

public static Canvas responsive(int initialWidth,
                                int initialHeight,
                                float minZoom,
                                float maxZoom)

Creates a canvas that resizes itself to match the screen size, as long as the zoom level stays within the specified bounds.