org.netbeans.editor.view.spi

Class ViewRenderingContext

java.lang.Object

org.netbeans.editor.view.spi.ViewRenderingContext

public abstract class ViewRenderingContext
extends Object

Context used for rendering of a view. It provides methods useful for measuring of the view contents.
It also provides information about additional highlights that the view should respect when painting a particular text.

A particular view can obtain an instance of ViewRenderingContext by using methods in RenderingContextView.

Only one thread at the time can safely use the rendering context. It does not have to be event dispatch thread.

Constructor Summary

Constructors

Constructor and Description
ViewRenderingContext()

Method Summary

Modifier and Type	Method and Description
abstract float	getAscent(View v)
abstract int	getBoundedPosition(View v, int p0, float x, float len) Determines the model location that represents the maximum advance that fits within the given span.
abstract float	getDescent(View v)
abstract float	getHeight(View v)
int	getNextVisualPositionFrom(View v, int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet) Provides a way to determine the next visually represented model location that one might place a caret.
abstract float	getSpan(View v, int p0, int p1, TabExpander e, float x)
abstract Shape	modelToView(View v, int pos, Position.Bias bias, Shape a) Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.
static ViewRenderingContext	obtainContext(View v) Find instance of the ViewRenderingContext for the given view.
abstract void	paint(View v, Graphics g, Shape a, int p0, int p1) Paint the glyphs representing the given range.
abstract int	viewToModel(View v, float x, float y, Shape a, Position.Bias[] biasReturn) Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Methods inherited from class java.lang.Object

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

Constructor Detail

ViewRenderingContext

public ViewRenderingContext()

Method Detail

obtainContext

public static ViewRenderingContext obtainContext(View v)

Find instance of the ViewRenderingContext for the given view.

getSpan

public abstract float getSpan(View v,
                              int p0,
                              int p1,
                              TabExpander e,
                              float x)

getHeight

public abstract float getHeight(View v)

getAscent

public abstract float getAscent(View v)

getDescent

public abstract float getDescent(View v)

paint

public abstract void paint(View v,
                           Graphics g,
                           Shape a,
                           int p0,
                           int p1)

Paint the glyphs representing the given range.

modelToView

public abstract Shape modelToView(View v,
                                  int pos,
                                  Position.Bias bias,
                                  Shape a)
                           throws BadLocationException

Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it. This is shared by the broken views.

Parameters:

pos - the position to convert

a - the allocated region to render into

bias - enum to choose rendering side

Returns:

the bounding box of the given position

Throws:

BadLocationException - if the given position does not represent a valid location in the associated document

See Also:

View.modelToView(int, java.awt.Shape, javax.swing.text.Position.Bias)

viewToModel

public abstract int viewToModel(View v,
                                float x,
                                float y,
                                Shape a,
                                Position.Bias[] biasReturn)

Provides a mapping from the view coordinate space to the logical coordinate space of the model.

Parameters:

x - the X coordinate

y - the Y coordinate

a - the allocated region to render into

biasReturn - enum to choose rendering side

Returns:

the location within the model that best represents the given point of view

See Also:

View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])

getBoundedPosition

public abstract int getBoundedPosition(View v,
                                       int p0,
                                       float x,
                                       float len)

Determines the model location that represents the maximum advance that fits within the given span. This could be used to break the given view. The result should be a location just shy of the given advance. This differs from viewToModel which returns the closest position which might be proud of the maximum advance.

Parameters:

v - the view to find the model location to break at.

p0 - the location in the model where the fragment should start it's representation >= 0.

x - the graphic location along the axis that the broken view would occupy >= 0. This may be useful for things like tab calculations.

len - specifies the distance into the view where a potential break is desired >= 0.

Returns:

the maximum model location possible for a break.

See Also:

View.breakView(int, int, float, float)

getNextVisualPositionFrom

public int getNextVisualPositionFrom(View v,
                                     int pos,
                                     Position.Bias b,
                                     Shape a,
                                     int direction,
                                     Position.Bias[] biasRet)
                              throws BadLocationException

Provides a way to determine the next visually represented model location that one might place a caret. Some views may not be visible, they might not be in the same order found in the model, or they just might not allow access to some of the locations in the model.

Parameters:

v - the view to use

pos - the position to convert >= 0

a - the allocated region to render into

direction - the direction from the current position that can be thought of as the arrow keys typically found on a keyboard. This may be SwingConstants.WEST, SwingConstants.EAST, SwingConstants.NORTH, or SwingConstants.SOUTH.

Returns:

the location within the model that best represents the next location visual position.

Throws:

BadLocationException

IllegalArgumentException - for an invalid direction