com.nokia.mid.ui
Class CanvasItem

java.lang.Object
  com.nokia.mid.ui.CanvasItem

Direct Known Subclasses:

BrowserItem, CanvasGraphicsItem, TextEditor

public abstract class CanvasItem
extends java.lang.Object

Field Summary

static int	SCALE_AVERAGE Constant used to indicate the SCALE_AVERAGE mode of a CanvasItem.
static int	SCALE_NEAREST Constant used to indicate the SCALE_NEAREST mode of a CanvasItem.
static int	SCALE_NOT_ALLOWED Constant used to indicate the SCALE_NOT_ALLOWED mode of a CanvasItem.

Method Summary

int	getHeight() Gets the height of this CanvasItem in pixels.
java.lang.Object	getParent() Gets the current parent of this CanvasItem
int	getPositionX() Gets the rendering position of this CanvasItem.
int	getPositionY() Sets the rendering position of this CanvasItem.
int	getWidth() Gets the width of this CanvasItem in pixels.
int	getZPosition() Returns the Z-position, or the elevation, of the item.
protected static boolean	isValidImageAnchor(int anchor) Tests whether anchor has valid values
boolean	isVisible() Returns the current visibility of this CanvasItem
void	scale(int width, int height) Scales CanvasItem to the specified size as per current scaling mode.
void	scale(int x, int y, int width, int height) Scales CanvasItem to the specified size as per current scaling mode and resets the current anchor position.
void	setParent(java.lang.Object theParent) Set the parent object of this CanvasItem.
void	setPosition(int x, int y) Sets the rendering position of this CanvasItem.
void	setScalingMode(int scaleMode, boolean aspectRatioPreserved, int anchor) This method is called to define how size change / scaling should be performed.
void	setSize(int width, int height) Sets the size of this Window in pixels.
void	setSize(int x, int y, int width, int height) Sets the size of this CanvasItem in pixels and resets the current anchor position.
void	setVisible(boolean visible) Sets the visibility value of CanvasItem.
void	setZPosition(int z) Sets the Z-position, or the elevation, of the item.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SCALE_NOT_ALLOWED

public static final int SCALE_NOT_ALLOWED

Constant used to indicate the SCALE_NOT_ALLOWED mode of a CanvasItem.

This might be passed as a parameter to #setScalingMode(int, boolean) if window is intended not to allow scaling.

Constant value 0x0 is set to SCALE_NOT_ALLOWED.

See Also:

Constant Field Values

SCALE_NEAREST

public static final int SCALE_NEAREST

Constant used to indicate the SCALE_NEAREST mode of a CanvasItem.

This might be passed as a parameter to #setScalingMode(int, boolean) if window is intended be in a nearest neighbor scaling mode.

Constant value 0x1 is set to SCALE_NEAREST.

See Also:

Constant Field Values

SCALE_AVERAGE

public static final int SCALE_AVERAGE

Constant used to indicate the SCALE_AVERAGE mode of a CanvasItem.

This might be passed as a parameter to #setScalingMode(int, boolean) if window is intended to be in a "interpolate using average" scaling mode .

Constant value 0x2 is set to SCALE_AVERAGE.

See Also:

Constant Field Values

Method Detail

setParent

public void setParent(java.lang.Object theParent)

Set the parent object of this CanvasItem. Typically in the parent object would be Canvas or CustomItem. Setting the parameter to null removes the association to the parent. If setParent(null) is called for a CanvasItem yet not having any parent the call is silently ignored.

Parameters:

theParent - the parent object

Throws:

java.lang.IllegalArgumentException - if parent is not a valid object with which a TextEditor can be associated, or if CanvasItem is already set to another another parent

setSize

public void setSize(int width,
                    int height)
             throws java.lang.IllegalArgumentException

Sets the size of this Window in pixels.

Parameters:

width - width in pixels

height - height in pixels

Throws:

java.lang.IllegalArgumentException - if the width or height is less than one pixel

See Also:

for more details

setSize

public void setSize(int x,
                    int y,
                    int width,
                    int height)

Sets the size of this CanvasItem in pixels and resets the current anchor position.

This call has the same effect as calling consecutively the following two methods setSize(int, int) and setPosition(int, int).

Parameters:

x - the x coordinate of the anchor point

y - the y coordinate of the anchor point

width - the new width in pixels

height - the new height in pixels

Throws:

java.lang.IllegalArgumentException - if the width or height is less than one pixel

See Also:

setPosition(int, int), setSize(int, int)

getHeight

public int getHeight()

Gets the height of this CanvasItem in pixels.

Returns:

height in pixels

getWidth

public int getWidth()

Gets the width of this CanvasItem in pixels.

Returns:

width in pixels

setPosition

public void setPosition(int x,
                        int y)

Sets the rendering position of this CanvasItem. The origin is relative to the coordinate system of parent.

The CanvasItem may be placed partially or fully off of the visible area of the parent by the setPosition method; in this case the CanvasItem is just not fully visible.

Parameters:

x - the x coordinate of the anchor point, in pixels.

y - the y coordinate of the anchor point, in pixels.

setZPosition

public void setZPosition(int z)
                  throws java.lang.IllegalArgumentException

Sets the Z-position, or the elevation, of the item. The elevation decides the stacking order of neighboring items. An item of high Z-position will be drawn on top of an item with a lower Z-position if they share the same parent item. Other items that share the same Z-position will be drawn in an undefined order, although the order will stay the same for as long as the items live. The Z-position does not affect the item's size in any way. When items are added with setParent they will get a Z-position that is increased by 1 from the previously added item.

Parameters:

z - the z position of the item.

Throws:

java.lang.IllegalArgumentException - If z < 0

See Also:

getZPosition()

getPositionX

public int getPositionX()

Gets the rendering position of this CanvasItem. The origin is relative to the coordinate system of parent.

Returns:

X location of the CanvasItem

getPositionY

public int getPositionY()

Sets the rendering position of this CanvasItem. The origin is relative to the coordinate system of parent.

The CanvasItem may be placed partially or fully off of the visible area of the parent by the setPosition method; in this case the CanvasItem is just not fully visible.

Returns:

Y location of the CanvasItem

getZPosition

public int getZPosition()

Returns the Z-position, or the elevation, of the item. The Z-position decides the stacking order of neighboring items.

See Also:

#getZPosition(int)

setVisible

public void setVisible(boolean visible)

Sets the visibility value of CanvasItem. Initially CanvasItem is not visible so it must be explicitly set to visible in order it to appear on UI.

If the editor is already visible calling setVisible(true) does nothing. If the item is not visible calling setVisible(false) does nothing.

Throws:

java.lang.IllegalStateException - If its visibility is locked by the platform.

isVisible

public boolean isVisible()

Returns the current visibility of this CanvasItem

Returns:

true if currently visible, false otherwise

scale

public void scale(int width,
                  int height)

Scales CanvasItem to the specified size as per current scaling mode.

Parameters:

width - the new width in pixels

height - the new height in pixels

See Also:

scalling mode settings

scale

public void scale(int x,
                  int y,
                  int width,
                  int height)

Scales CanvasItem to the specified size as per current scaling mode and resets the current anchor position.

Parameters:

x - the x coordinate of the anchor point

y - the y coordinate of the anchor point

width - the new width in pixels

height - the new height in pixels

See Also:

scaling mode settings, setPosition(int, int), scale(int, int)

setScalingMode

public void setScalingMode(int scaleMode,
                           boolean aspectRatioPreserved,
                           int anchor)

This method is called to define how size change / scaling should be performed.

Parameters:

scaleMode - scaling mode: SCALE_NEAREST or SCALE_AVERAGE or SCALE_NOT_ALLOWED

aspectRatioPreserved - set to true to preserve aspect ration when scaling

anchor - the anchor point for positioning the window

Throws:

java.lang.IllegalArgumentException - if scaleMode or/and anchor are not a legal values.

See Also:

for more details

getParent

public java.lang.Object getParent()

Gets the current parent of this CanvasItem

Returns:

the current parent

isValidImageAnchor

protected static boolean isValidImageAnchor(int anchor)

Tests whether anchor has valid values

Parameters:

anchor - anchor value to be tested

Returns:

true if anchor is valid, otherwise false