Package eu.webtoolkit.jwt

Class WPainterPath

java.lang.Object
eu.webtoolkit.jwt.WJavaScriptExposableObject
eu.webtoolkit.jwt.WPainterPath
public class WPainterPath extends WJavaScriptExposableObject
A path defining a shape.

A painter path represents a (complex) path that may be composed of lines, arcs and bezier curve segments, and painted onto a paint device using WPainter#drawPath().

The path that is composed in a painter path may consist of multiple closed sub-paths. Only the last sub-path can be left open.

To compose a path, this class maintains a current position, which is the starting point for the next drawing operation. An operation may draw a line (see lineTo()), arc (see arcTo()), or bezier curve (see quadTo() and cubicTo()) from the current position to a new position. A new sub path may be started by moving the current position to a new location (see moveTo()), which automatically closes the previous sub path.

When sub paths overlap, the result is undefined (it is dependent on the underlying painting device).

Usage example: 


 WPainter painter = new WPainter();

 WPainterPath path = new WPainterPath(new WPointF(10, 10));
 path.lineTo(10, 20);
 path.lineTo(30, 20);
 path.closeSubPath();

 painter.setPen(new WPen(WColor.red));
 painter.setBrush(new WBrush(WColor.blue));
 painter.drawPath(path);

JavaScript exposability

A WPainterPath is JavaScript exposable. If a WPainterPath is JavaScript bound, it can be accessed in your custom JavaScript code through its handle's jsRef().

A WPainterPath is represented in JavaScript as an array of segments, where each segment is defined by a three element array: [x,y,type], where type is the integer representation of the type of a segment.

For example, a 10 by 10 square with the top left at (10,10) is represented as: 


 [
 [10,10,0], // move to (10,10)
 [20,10,1], // line to (20,10)
 [20,20,1], // line to (20,20)
 [10,20,1], // line to (10,20)
 [10,10,1]  // line to (10,10)
 ]

Warning: A WPainterPath that is JavaScript exposed should be modified only through its handle. Any attempt at modifying it will cause an exception to be thrown.

See Also:

  • Constructor Details

    • WPainterPath

      public WPainterPath()
      Default constructor.

      Creates an empty path, and sets the current position to (0, 0).

    • WPainterPath

      public WPainterPath(WPointF startPoint)
      Construct a new path, and set the initial position.

      Creates an empty path, and sets the current position to startPoint.

    • WPainterPath

      public WPainterPath(WPainterPath path)
      Copy constructor.

  • Method Details

    • assign

      public WPainterPath assign(WPainterPath path)
      Assignment method.

    • clone

      public WPainterPath clone()
      Specified by:
      clone in class WJavaScriptExposableObject

    • getCurrentPosition

      public WPointF getCurrentPosition()
      Returns the current position.

      Returns the current position, which is the end point of the last move or draw operation, and which well be the start point of the next draw operation.

    • isEmpty

      public boolean isEmpty()
      Returns whether the path is empty.

      Returns true if the path contains no drawing operations. Note that move operations are not considered drawing operations.

    • equals

      public boolean equals(WPainterPath path)
      Indicates whether some other object is "equal to" this one.

      Returns true if the paths are exactly the same.

    • closeSubPath

      public void closeSubPath()
      Closes the last sub path.

      Draws a line from the current position to the start position of the last sub path (which is the end point of the last move operation), and sets the current position to (0, 0).

    • moveTo

      public void moveTo(WPointF point)
      Moves the current position to a new location.

      Moves the current position to a new point, implicitly closing the last sub path, unless open subpaths are enabled.

      See Also:

    • moveTo

      public void moveTo(double x, double y)
      Moves the current position to a new location.

      Moves the current position to a new point, implicitly closing the last sub path, unless open subpaths are enabled.

      See Also:

    • lineTo

      public void lineTo(WPointF point)
      Draws a straight line.

      Draws a straight line from the current position to point, which becomes the new current position.

      See Also:

    • lineTo

      public void lineTo(double x, double y)
      Draws a straight line.

      Draws a straight line from the current position to (x, y), which becomes the new current position.

      See Also:

    • cubicTo

      public void cubicTo(WPointF c1, WPointF c2, WPointF endPoint)
      Draws a cubic bezier curve.

      Draws a cubic bezier curve from the current position to endPoint, which becomes the new current position. The bezier curve uses the two control points c1 and c2 .

      See Also:

    • cubicTo

      public void cubicTo(double c1x, double c1y, double c2x, double c2y, double endPointx, double endPointy)
      Draws a cubic bezier curve.

      This is an overloaded method provided for convenience.

      See Also:

    • arcTo

      public void arcTo(double cx, double cy, double radius, double startAngle, double sweepLength)
      Draws an arc.

      Draws an arc which is a segment of a circle. The circle is defined with center (cx, cy) and radius. The segment starts at startAngle, and spans an angle given by spanAngle. These angles are expressed in degrees, and are measured counter-clockwise starting from the 3 o'clock position.

      Implicitly draws a line from the current position to the start of the arc, if the current position is different from the start.

      See Also:

    • arcMoveTo

      public void arcMoveTo(double cx, double cy, double radius, double angle)
      Moves to a point on an arc.

      Moves to a point on a circle. The circle is defined with center (cx, cy) and radius, and the point is at angle degrees measured counter-clockwise starting from the 3 o'clock position.

      See Also:

    • arcMoveTo

      public void arcMoveTo(double x, double y, double width, double height, double angle)
      Move to a point on an arc.

      Moves to a point on an ellipse. The ellipse fits in the rectangle defined by top left position (x, y), and size width x height, and the point is at angle degrees measured counter-clockwise starting from the 3 o'clock position.

      See Also:

    • quadTo

      public void quadTo(WPointF c, WPointF endPoint)
      Draws a quadratic bezier curve.

      Draws a quadratic bezier curve from the current position to endPoint, which becomes the new current position. The bezier curve uses the single control point c .

      See Also:

    • quadTo

      public void quadTo(double cx, double cy, double endPointX, double endPointY)
      Draws a quadratic bezier curve.

      This is an overloaded method provided for convenience.

      See Also:

    • addEllipse

      public void addEllipse(WRectF rect)
      Draws an ellipse.

      This method closes the current sub path, and adds an ellipse that is bounded by the rectangle boundingRectangle.

      Note: some renderers only support circles (width == height)

      See Also:

    • addEllipse

      public void addEllipse(double x, double y, double width, double height)
      Draws an ellipse.

      This method closes the current sub path, and adds an ellipse that is bounded by the rectangle defined by top left position (x, y), and size width x height.

      Note: Some renderers only support circles (width == height)

      See Also:

    • addRect

      public void addRect(WRectF rectangle)
      Draws a rectangle.

      This method closes the current sub path, unless open subpaths are enabled, and adds a rectangle that is defined by rectangle.

      See Also:

    • addRect

      public void addRect(double x, double y, double width, double height)
      Draws a rectangle.

      This method closes the current sub path, unless open subpaths are enabled, and adds a rectangle that is defined by top left position (x, y), and size width x height.

      See Also:

    • addPolygon

      public void addPolygon(List<WPointF> points)
      Adds a polygon.

      If the first point is different from the current position, the last sub path is first closed, unless open subpaths are enabled, otherwise the last sub path is extended with the polygon.

      See Also:

    • addPath

      public void addPath(WPainterPath path)
      Adds a path.

      Adds an entire path to the current path. If the path's begin position is different from the current position, the last sub path is first closed, unless open subpaths are enabled, otherwise the last sub path is extended with the path's first sub path.

      See Also:

    • connectPath

      public void connectPath(WPainterPath path)
      Adds a path, connecting.

      Adds an entire path to the current path. If the path's begin position is different from the current position, the last sub path is first closed, unless open subpaths are enabled, otherwise the last sub path is extended with the path's first sub path.

      See Also:

    • getSegments

      public List<WPainterPath.Segment> getSegments()

    • getControlPointRect

      public WRectF getControlPointRect(WTransform transform)
      Returns the bounding box of the control points.

      Returns the bounding box of all control points. This is guaranteed to be a superset of the actual bounding box.

      The transform is applied to the path first.

    • getControlPointRect

      public final WRectF getControlPointRect()
      Returns the bounding box of the control points.

      Returns getControlPointRect(WTransform.Identity)

    • getCrisp

      public WPainterPath getCrisp()
      Returns a copy of the path where straight lines are moved to be rendered crisply.

      This is intended to be used on rectangles, or other paths consisting of only straight line, and will nudge every edge a little bit, so that 1px straight lines are rendered as a crisp line.

      This will also work if the path is JavaScript bound.

    • setOpenSubPathsEnabled

      public void setOpenSubPathsEnabled(boolean enabled)
      Disables automatically closing subpaths on moveTo.

      By default, open sub paths are disabled, and moveTo and any operation that relies on moveTo will automatically close the last subpath. Enabling this option disables that feature.

      See Also:

    • setOpenSubPathsEnabled

      public final void setOpenSubPathsEnabled()
      Disables automatically closing subpaths on moveTo.

      Calls setOpenSubPathsEnabled(true)

    • isOpenSubPathsEnabled

      public boolean isOpenSubPathsEnabled()
      Returns whether open subpaths are enabled.

      See Also:

    • getJsValue

      public String getJsValue()
      Description copied from class: WJavaScriptExposableObject
      Returns a JavaScript representation of the value of this object.

      Note: The value returned will reflect the current server side value of the object. If this object is JavaScript bound, this value may not reflect the actual client side value. If you need access to the client side value, use getJsRef() intead.

      Specified by:
      getJsValue in class WJavaScriptExposableObject

    • assignFromJSON

      protected void assignFromJSON(com.google.gson.JsonElement value)
      Specified by:
      assignFromJSON in class WJavaScriptExposableObject