Class Geometry


  • public class Geometry
    extends Object
    Contains static methods for performing simple geometric operations on the SWT geometry classes.
    Since:
    3.0
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static Point add​(Point point1, Point point2)
      Adds two points as 2d vectors.
      static Rectangle add​(Rectangle rect1, Rectangle rect2)
      Returns a new Rectangle whose x, y, width, and height is the sum of the x, y, width, and height values of both rectangles respectively.
      static Point centerPoint​(Rectangle rect)
      Returns the point in the center of the given rectangle.
      static Point copy​(Point toCopy)
      Returns a copy of the given point
      static Rectangle copy​(Rectangle toCopy)
      Returns a copy of the given rectangle
      static Rectangle createDiffRectangle​(int left, int right, int top, int bottom)
      Returns a rectangle which, when added to another rectangle, will expand each side by the given number of units.
      static Rectangle createRectangle​(Point position, Point size)
      Returns a new rectangle with the given position and dimensions, expressed as points.
      static int distanceSquared​(Point p1, Point p2)
      Returns the square of the distance between two points.
      static Point divide​(Point toDivide, int scalar)
      Divides both coordinates of the given point by the given scalar.
      static int dotProduct​(Point p1, Point p2)
      Returns the dot product of the given vectors (expressed as Points)
      static void expand​(Rectangle rect, int left, int right, int top, int bottom)
      Moves each edge of the given rectangle outward by the given amount.
      static void expand​(Rectangle rect, Rectangle differenceRect)
      Moves each edge of the given rectangle outward by the given amount.
      static void flipXY​(Point toFlip)
      Swaps the X and Y coordinates of the given point.
      static void flipXY​(Rectangle toFlip)
      Swaps the X and Y coordinates of the given rectangle, along with the height and width.
      static int getClosestSide​(Rectangle boundary, Point toTest)
      Returns the edge of the given rectangle is closest to the given point.
      static int getCoordinate​(Point toMeasure, boolean width)
      Returns the x or y coordinates of the given point.
      static int getCoordinate​(Rectangle toMeasure, boolean width)
      Returns the x or y coordinates of the given rectangle.
      static int getDimension​(Rectangle toMeasure, boolean width)
      Returns the height or width of the given rectangle.
      static Point getDirectionVector​(int distance, int direction)
      Returns a vector in the given direction with the given magnitude.
      static int getDistanceFrom​(Rectangle boundary, Point toTest)
      Returns the distance from the point to the nearest edge of the given rectangle.
      static int getDistanceFromEdge​(Rectangle rectangle, Point testPoint, int edgeOfInterest)
      Returns the distance of the given point from a particular side of the given rectangle.
      static Rectangle getExtrudedEdge​(Rectangle toExtrude, int size, int orientation)
      Extrudes the given edge inward by the given distance.
      static Point getLocation​(Rectangle toQuery)
      Returns the x,y position of the given rectangle.
      static int getOppositeSide​(int swtDirectionConstant)
      Returns the opposite of the given direction.
      static int getRelativePosition​(Rectangle boundary, Point toTest)
      Determines where the given point lies with respect to the given rectangle.
      static Point getSize​(Rectangle rectangle)
      Returns the size of the rectangle, as a Point
      static int getSwtHorizontalOrVerticalConstant​(boolean horizontal)
      Converts the given boolean into an SWT orientation constant.
      static boolean isHorizontal​(int swtSideConstant)
      Returns true iff the given SWT side constant corresponds to a horizontal side of a rectangle.
      static double magnitude​(Point p)
      Returns the magnitude of the given 2d vector (represented as a Point)
      static int magnitudeSquared​(Point p)
      Returns the square of the magnitude of the given 2-space vector (represented using a point)
      static Point max​(Point p1, Point p2)
      Returns a new point whose coordinates are the maximum of the coordinates of the given points
      static Point min​(Point p1, Point p2)
      Returns a new point whose coordinates are the minimum of the coordinates of the given points
      static void moveInside​(Rectangle inner, Rectangle outer)
      Repositions the 'inner' rectangle to lie completely within the bounds of the 'outer' rectangle if possible.
      static void moveRectangle​(Rectangle rect, Point delta)
      Moves the given rectangle by the given delta.
      static void normalize​(Rectangle rect)
      Normalizes the given rectangle.
      static void set​(Point result, Point toCopy)
      Sets result equal to toCopy
      static void set​(Rectangle result, Rectangle toCopy)
      Sets result equal to toCopy
      static void setCoordinate​(Point toSet, boolean width, int newCoordinate)
      Sets one coordinate of the given point.
      static void setCoordinate​(Rectangle toSet, boolean width, int newCoordinate)
      Sets one coordinate of the given rectangle.
      static void setDimension​(Rectangle toSet, boolean width, int newCoordinate)
      Sets one dimension of the given rectangle.
      static void setLocation​(Rectangle rectangle, Point newLocation)
      Sets the x,y position of the given rectangle.
      static void setSize​(Rectangle rectangle, Point newSize)
      Sets the size of the given rectangle to the given size
      static Point subtract​(Point point1, Point point2)
      Performs vector subtraction on two points.
      static Rectangle subtract​(Rectangle rect1, Rectangle rect2)
      Returns a new difference Rectangle whose x, y, width, and height are equal to the difference of the corresponding attributes from the given rectangles
      static Rectangle toControl​(Control coordinateSystem, Rectangle toConvert)
      Converts the given rectangle from display coordinates to the local coordinate system of the given object into display coordinates.
      static Rectangle toDisplay​(Control coordinateSystem, Rectangle toConvert)
      Converts the given rectangle from the local coordinate system of the given object into display coordinates.
    • Method Detail

      • distanceSquared

        public static int distanceSquared​(Point p1,
                                          Point p2)
        Returns the square of the distance between two points.

        This is preferred over the real distance when searching for the closest point, since it avoids square roots.

        Parameters:
        p1 - first endpoint
        p2 - second endpoint
        Returns:
        the square of the distance between the two points
        Since:
        3.0
      • magnitude

        public static double magnitude​(Point p)
        Returns the magnitude of the given 2d vector (represented as a Point)
        Parameters:
        p - point representing the 2d vector whose magnitude is being computed
        Returns:
        the magnitude of the given 2d vector
        Since:
        3.0
      • magnitudeSquared

        public static int magnitudeSquared​(Point p)
        Returns the square of the magnitude of the given 2-space vector (represented using a point)
        Parameters:
        p - the point whose magnitude is being computed
        Returns:
        the square of the magnitude of the given vector
        Since:
        3.0
      • dotProduct

        public static int dotProduct​(Point p1,
                                     Point p2)
        Returns the dot product of the given vectors (expressed as Points)
        Parameters:
        p1 - the first vector
        p2 - the second vector
        Returns:
        the dot product of the two vectors
        Since:
        3.0
      • min

        public static Point min​(Point p1,
                                Point p2)
        Returns a new point whose coordinates are the minimum of the coordinates of the given points
        Parameters:
        p1 - a Point
        p2 - a Point
        Returns:
        a new point whose coordinates are the minimum of the coordinates of the given points
        Since:
        3.0
      • max

        public static Point max​(Point p1,
                                Point p2)
        Returns a new point whose coordinates are the maximum of the coordinates of the given points
        Parameters:
        p1 - a Point
        p2 - a Point
        Returns:
        point a new point whose coordinates are the maximum of the coordinates
        Since:
        3.0
      • getDirectionVector

        public static Point getDirectionVector​(int distance,
                                               int direction)
        Returns a vector in the given direction with the given magnitude. Directions are given using SWT direction constants, and the resulting vector is in the screen's coordinate system. That is, the vector (0, 1) is down and the vector (1, 0) is right.
        Parameters:
        distance - magnitude of the vector
        direction - one of SWT.TOP, SWT.BOTTOM, SWT.LEFT, or SWT.RIGHT
        Returns:
        a point representing a vector in the given direction with the given magnitude
        Since:
        3.0
      • centerPoint

        public static Point centerPoint​(Rectangle rect)
        Returns the point in the center of the given rectangle.
        Parameters:
        rect - rectangle being computed
        Returns:
        a Point at the center of the given rectangle.
        Since:
        3.0
      • copy

        public static Point copy​(Point toCopy)
        Returns a copy of the given point
        Parameters:
        toCopy - point to copy
        Returns:
        a copy of the given point
      • set

        public static void set​(Point result,
                               Point toCopy)
        Sets result equal to toCopy
        Parameters:
        result - object that will be modified
        toCopy - object that will be copied
        Since:
        3.1
      • set

        public static void set​(Rectangle result,
                               Rectangle toCopy)
        Sets result equal to toCopy
        Parameters:
        result - object that will be modified
        toCopy - object that will be copied
        Since:
        3.1
      • subtract

        public static Rectangle subtract​(Rectangle rect1,
                                         Rectangle rect2)

        Returns a new difference Rectangle whose x, y, width, and height are equal to the difference of the corresponding attributes from the given rectangles

        Example: Compute the margins for a given Composite, and apply those same margins to a new GridLayout
         
              // Compute the client area, in the coordinate system of the input composite's parent
              Rectangle clientArea = Display.getCurrent().map(inputComposite,
                inputComposite.getParent(), inputComposite.getClientArea());
        
              // Compute the margins for a given Composite by subtracting the client area from the composite's bounds
              Rectangle margins = Geometry.subtract(inputComposite.getBounds(), clientArea);
        
              // Now apply these margins to a new GridLayout
              GridLayout layout = GridLayoutFactory.fillDefaults().margins(margins).create();
         
         
        Parameters:
        rect1 - first rectangle
        rect2 - rectangle to subtract
        Returns:
        the difference between the two rectangles (computed as rect1 - rect2)
        Since:
        3.3
      • add

        public static Rectangle add​(Rectangle rect1,
                                    Rectangle rect2)

        Returns a new Rectangle whose x, y, width, and height is the sum of the x, y, width, and height values of both rectangles respectively.

        Parameters:
        rect1 - first rectangle to add
        rect2 - second rectangle to add
        Returns:
        a new rectangle whose x, y, height, and width attributes are the sum of the corresponding attributes from the arguments.
        Since:
        3.3
      • add

        public static Point add​(Point point1,
                                Point point2)
        Adds two points as 2d vectors. Returns a new point whose coordinates are the sum of the original two points.
        Parameters:
        point1 - the first point (not null)
        point2 - the second point (not null)
        Returns:
        a new point whose coordinates are the sum of the given points
        Since:
        3.0
      • divide

        public static Point divide​(Point toDivide,
                                   int scalar)
        Divides both coordinates of the given point by the given scalar.
        Parameters:
        toDivide - point to divide
        scalar - denominator
        Returns:
        a new Point whose coordinates are equal to the original point divided by the scalar
        Since:
        3.1
      • subtract

        public static Point subtract​(Point point1,
                                     Point point2)
        Performs vector subtraction on two points. Returns a new point equal to (point1 - point2).
        Parameters:
        point1 - initial point
        point2 - vector to subtract
        Returns:
        the difference (point1 - point2)
        Since:
        3.0
      • flipXY

        public static void flipXY​(Point toFlip)
        Swaps the X and Y coordinates of the given point.
        Parameters:
        toFlip - modifies this point
        Since:
        3.1
      • flipXY

        public static void flipXY​(Rectangle toFlip)
        Swaps the X and Y coordinates of the given rectangle, along with the height and width.
        Parameters:
        toFlip - modifies this rectangle
        Since:
        3.1
      • getDimension

        public static int getDimension​(Rectangle toMeasure,
                                       boolean width)
        Returns the height or width of the given rectangle.
        Parameters:
        toMeasure - rectangle to measure
        width - returns the width if true, and the height if false
        Returns:
        the width or height of the given rectangle
        Since:
        3.0
      • getCoordinate

        public static int getCoordinate​(Point toMeasure,
                                        boolean width)
        Returns the x or y coordinates of the given point.
        Parameters:
        toMeasure - point being measured
        width - if true, returns x. Otherwise, returns y.
        Returns:
        the x or y coordinate
        Since:
        3.1
      • getCoordinate

        public static int getCoordinate​(Rectangle toMeasure,
                                        boolean width)
        Returns the x or y coordinates of the given rectangle.
        Parameters:
        toMeasure - rectangle being measured
        width - if true, returns x. Otherwise, returns y.
        Returns:
        the x or y coordinate
        Since:
        3.1
      • setDimension

        public static void setDimension​(Rectangle toSet,
                                        boolean width,
                                        int newCoordinate)
        Sets one dimension of the given rectangle. Modifies the given rectangle.
        Parameters:
        toSet - rectangle to modify
        width - if true, the width is modified. If false, the height is modified.
        newCoordinate - new value of the width or height
        Since:
        3.1
      • setCoordinate

        public static void setCoordinate​(Rectangle toSet,
                                         boolean width,
                                         int newCoordinate)
        Sets one coordinate of the given rectangle. Modifies the given rectangle.
        Parameters:
        toSet - rectangle to modify
        width - if true, the x coordinate is modified. If false, the y coordinate is modified.
        newCoordinate - new value of the x or y coordinates
        Since:
        3.1
      • setCoordinate

        public static void setCoordinate​(Point toSet,
                                         boolean width,
                                         int newCoordinate)
        Sets one coordinate of the given point. Modifies the given point.
        Parameters:
        toSet - point to modify
        width - if true, the x coordinate is modified. If false, the y coordinate is modified.
        newCoordinate - new value of the x or y coordinates
        Since:
        3.1
      • getDistanceFromEdge

        public static int getDistanceFromEdge​(Rectangle rectangle,
                                              Point testPoint,
                                              int edgeOfInterest)
        Returns the distance of the given point from a particular side of the given rectangle. Returns negative values for points outside the rectangle.
        Parameters:
        rectangle - a bounding rectangle
        testPoint - a point to test
        edgeOfInterest - side of the rectangle to test against
        Returns:
        the distance of the given point from the given edge of the rectangle
        Since:
        3.0
      • getExtrudedEdge

        public static Rectangle getExtrudedEdge​(Rectangle toExtrude,
                                                int size,
                                                int orientation)
        Extrudes the given edge inward by the given distance. That is, if one side of the rectangle was sliced off with a given thickness, this returns the rectangle that forms the slice. Note that the returned rectangle will be inside the given rectangle if size > 0.
        Parameters:
        toExtrude - the rectangle to extrude. The resulting rectangle will share three sides with this rectangle.
        size - distance to extrude. A negative size will extrude outwards (that is, the resulting rectangle will overlap the original iff this is positive).
        orientation - the side to extrude. One of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM. The resulting rectangle will always share this side with the original rectangle.
        Returns:
        a rectangle formed by extruding the given side of the rectangle by the given distance.
        Since:
        3.0
      • getOppositeSide

        public static int getOppositeSide​(int swtDirectionConstant)
        Returns the opposite of the given direction. That is, returns SWT.LEFT if given SWT.RIGHT and visa-versa.
        Parameters:
        swtDirectionConstant - one of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM
        Returns:
        one of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM
        Since:
        3.0
      • getSwtHorizontalOrVerticalConstant

        public static int getSwtHorizontalOrVerticalConstant​(boolean horizontal)
        Converts the given boolean into an SWT orientation constant.
        Parameters:
        horizontal - if true, returns SWT.HORIZONTAL. If false, returns SWT.VERTICAL
        Returns:
        SWT.HORIZONTAL or SWT.VERTICAL.
        Since:
        3.0
      • isHorizontal

        public static boolean isHorizontal​(int swtSideConstant)
        Returns true iff the given SWT side constant corresponds to a horizontal side of a rectangle. That is, returns true for the top and bottom but false for the left and right.
        Parameters:
        swtSideConstant - one of SWT.TOP, SWT.BOTTOM, SWT.LEFT, or SWT.RIGHT
        Returns:
        true iff the given side is horizontal.
        Since:
        3.0
      • moveRectangle

        public static void moveRectangle​(Rectangle rect,
                                         Point delta)
        Moves the given rectangle by the given delta.
        Parameters:
        rect - rectangle to move (will be modified)
        delta - direction vector to move the rectangle by
        Since:
        3.0
      • expand

        public static void expand​(Rectangle rect,
                                  Rectangle differenceRect)
        Moves each edge of the given rectangle outward by the given amount. Negative values cause the rectangle to contract. Does not allow the rectangle's width or height to be reduced below zero.
        Parameters:
        rect - normalized rectangle to modify
        differenceRect - difference rectangle to be added to rect
        Since:
        3.3
      • createDiffRectangle

        public static Rectangle createDiffRectangle​(int left,
                                                    int right,
                                                    int top,
                                                    int bottom)

        Returns a rectangle which, when added to another rectangle, will expand each side by the given number of units.

        This is commonly used to store margin sizes. For example:

         
             // Expands the left, right, top, and bottom
             // of the given control by 10, 5, 1, and 15 units respectively
        
             Rectangle margins = Geometry.createDifferenceRect(10,5,1,15);
             Rectangle bounds = someControl.getBounds();
             someControl.setBounds(Geometry.add(bounds, margins));
         
         
        Parameters:
        left - distance to expand the left side (negative values move the edge inward)
        right - distance to expand the right side (negative values move the edge inward)
        top - distance to expand the top (negative values move the edge inward)
        bottom - distance to expand the bottom (negative values move the edge inward)
        Returns:
        a difference rectangle that, when added to another rectangle, will cause each side to expand by the given number of units
        Since:
        3.3
      • expand

        public static void expand​(Rectangle rect,
                                  int left,
                                  int right,
                                  int top,
                                  int bottom)
        Moves each edge of the given rectangle outward by the given amount. Negative values cause the rectangle to contract. Does not allow the rectangle's width or height to be reduced below zero.
        Parameters:
        rect - normalized rectangle to modify
        left - distance to move the left edge outward (negative values move the edge inward)
        right - distance to move the right edge outward (negative values move the edge inward)
        top - distance to move the top edge outward (negative values move the edge inward)
        bottom - distance to move the bottom edge outward (negative values move the edge inward)
        Since:
        3.1
      • normalize

        public static void normalize​(Rectangle rect)
        Normalizes the given rectangle. That is, any rectangle with negative width or height becomes a rectangle with positive width or height that extends to the upper-left of the original rectangle.
        Parameters:
        rect - rectangle to modify
        Since:
        3.0
      • toControl

        public static Rectangle toControl​(Control coordinateSystem,
                                          Rectangle toConvert)
        Converts the given rectangle from display coordinates to the local coordinate system of the given object into display coordinates.
        Parameters:
        coordinateSystem - local coordinate system being converted to
        toConvert - rectangle to convert
        Returns:
        a rectangle in control coordinates
        Since:
        3.0
      • toDisplay

        public static Rectangle toDisplay​(Control coordinateSystem,
                                          Rectangle toConvert)
        Converts the given rectangle from the local coordinate system of the given object into display coordinates.
        Parameters:
        coordinateSystem - local coordinate system being converted from
        toConvert - rectangle to convert
        Returns:
        a rectangle in display coordinates
        Since:
        3.0
      • getRelativePosition

        public static int getRelativePosition​(Rectangle boundary,
                                              Point toTest)
        Determines where the given point lies with respect to the given rectangle. Returns a combination of SWT.LEFT, SWT.RIGHT, SWT.TOP, and SWT.BOTTOM, combined with bitwise or (for example, returns SWT.TOP | SWT.LEFT if the point is to the upper-left of the rectangle). Returns 0 if the point lies within the rectangle. Positions are in screen coordinates (ie: a point is to the upper-left of the rectangle if its x and y coordinates are smaller than any point in the rectangle)
        Parameters:
        boundary - normalized boundary rectangle
        toTest - point whose relative position to the rectangle is being computed
        Returns:
        one of SWT.LEFT | SWT.TOP, SWT.TOP, SWT.RIGHT | SWT.TOP, SWT.LEFT, 0, SWT.RIGHT, SWT.LEFT | SWT.BOTTOM, SWT.BOTTOM, SWT.RIGHT | SWT.BOTTOM
        Since:
        3.0
      • getDistanceFrom

        public static int getDistanceFrom​(Rectangle boundary,
                                          Point toTest)
        Returns the distance from the point to the nearest edge of the given rectangle. Returns negative values if the point lies outside the rectangle.
        Parameters:
        boundary - rectangle to test
        toTest - point to test
        Returns:
        the distance between the given point and the nearest edge of the rectangle. Returns positive values for points inside the rectangle and negative values for points outside the rectangle.
        Since:
        3.1
      • getClosestSide

        public static int getClosestSide​(Rectangle boundary,
                                         Point toTest)
        Returns the edge of the given rectangle is closest to the given point.
        Parameters:
        boundary - rectangle to test
        toTest - point to compare
        Returns:
        one of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM
        Since:
        3.0
      • copy

        public static Rectangle copy​(Rectangle toCopy)
        Returns a copy of the given rectangle
        Parameters:
        toCopy - rectangle to copy
        Returns:
        a copy of the given rectangle
        Since:
        3.0
      • getSize

        public static Point getSize​(Rectangle rectangle)
        Returns the size of the rectangle, as a Point
        Parameters:
        rectangle - rectangle whose size is being computed
        Returns:
        the size of the given rectangle
        Since:
        3.0
      • setSize

        public static void setSize​(Rectangle rectangle,
                                   Point newSize)
        Sets the size of the given rectangle to the given size
        Parameters:
        rectangle - rectangle to modify
        newSize - new size of the rectangle
        Since:
        3.0
      • setLocation

        public static void setLocation​(Rectangle rectangle,
                                       Point newLocation)
        Sets the x,y position of the given rectangle. For a normalized rectangle (a rectangle with positive width and height), this will be the upper-left corner of the rectangle.
        Parameters:
        rectangle - rectangle to modify
        newLocation - new location of the rectangle
        Since:
        3.0
      • getLocation

        public static Point getLocation​(Rectangle toQuery)
        Returns the x,y position of the given rectangle. For normalized rectangles (rectangles with positive width and height), this is the upper-left corner of the rectangle.
        Parameters:
        toQuery - rectangle to query
        Returns:
        a Point containing the x,y position of the rectangle
        Since:
        3.0
      • createRectangle

        public static Rectangle createRectangle​(Point position,
                                                Point size)
        Returns a new rectangle with the given position and dimensions, expressed as points.
        Parameters:
        position - the (x,y) position of the rectangle
        size - the size of the new rectangle, where (x,y) -> (width, height)
        Returns:
        a new Rectangle with the given position and size
        Since:
        3.0
      • moveInside

        public static void moveInside​(Rectangle inner,
                                      Rectangle outer)
        Repositions the 'inner' rectangle to lie completely within the bounds of the 'outer' rectangle if possible. One use for this is to ensure that, when setting a control's bounds, that they will always lie within its parent's client area (to avoid clipping).
        Parameters:
        inner - The 'inner' rectangle to be repositioned (should be smaller than the 'outer' rectangle)
        outer - The 'outer' rectangle