android.graphics
Class RectF

java.lang.Object
  android.graphics.RectF

public class RectF
extends Object

RectF holds four float coordinates for a rectangle. The rectangle is represented by the coordinates of its 4 edges (left, top, right bottom). These fields can be accessed directly. Use width() and height() to retrieve the rectangle's width and height. Note: most methods do not check to see that the coordinates are sorted correctly (i.e. left <= right and top <= bottom).

Field Summary

float	bottom
float	left
float	right
float	top

Constructor Summary

RectF()
Create a new empty RectF.

RectF(float left, float top, float right, float bottom)
Create a new rectangle with the specified coordinates.

RectF(Rect r)

RectF(RectF r)
Create a new rectangle, initialized with the values in the specified rectangle (which is left unmodified).

Method Summary

float	centerX()
float	centerY()
boolean	contains(float x, float y) Returns true if (x,y) is inside the rectangle.
boolean	contains(float left, float top, float right, float bottom) Returns true iff the 4 specified sides of a rectangle are inside or equal to this rectangle.
boolean	contains(RectF r) Returns true iff the specified rectangle r is inside or equal to this rectangle.
float	height()
void	inset(float dx, float dy) Inset the rectangle by (dx,dy).
boolean	intersect(float left, float top, float right, float bottom) If the rectangle specified by left,top,right,bottom intersects this rectangle, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle.
boolean	intersect(RectF r) If the specified rectangle intersects this rectangle, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle.
boolean	intersects(float left, float top, float right, float bottom) Returns true if this rectangle intersects the specified rectangle.
static boolean	intersects(RectF a, RectF b) Returns true iff the two specified rectangles intersect.
boolean	isEmpty() Returns true if the rectangle is empty (left >= right or top >= bottom)
void	offset(float dx, float dy) Offset the rectangle by adding dx to its left and right coordinates, and adding dy to its top and bottom coordinates.
void	offsetTo(float newLeft, float newTop) Offset the rectangle to a specific (left, top) position, keeping its width and height the same.
void	round(Rect dst) Set the dst integer Rect by rounding this rectangle's coordinates to their nearest integer values.
void	roundOut(Rect dst) Set the dst integer Rect by rounding "out" this rectangle, choosing the floor of top and left, and the ceiling of right and bottom.
void	set(float left, float top, float right, float bottom) Set the rectangle's coordinates to the specified values.
void	set(Rect src) Copy the coordinates from src into this rectangle.
void	set(RectF src) Copy the coordinates from src into this rectangle.
void	setEmpty() Set the rectangle to (0,0,0,0)
boolean	setIntersect(RectF a, RectF b) If rectangles a and b intersect, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle.
void	sort() Swap top/bottom or left/right if there are flipped (i.e.
String	toString() Returns a string containing a concise, human-readable description of the receiver.
void	union(float x, float y) Update this Rect to enclose itself and the [x,y] coordinate.
void	union(float left, float top, float right, float bottom) Update this Rect to enclose itself and the specified rectangle.
void	union(RectF r) Update this Rect to enclose itself and the specified rectangle.
float	width()

Methods inherited from class java.lang.Object

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

Field Detail

left

public float left

top

public float top

right

public float right

bottom

public float bottom

Constructor Detail

RectF

public RectF()

Create a new empty RectF. All coordinates are initialized to 0.

RectF

public RectF(float left,
             float top,
             float right,
             float bottom)

Create a new rectangle with the specified coordinates. Note: no range checking is performed, so the caller must ensure that left <= right and top <= bottom.

Parameters:

left - The X coordinate of the left side of the rectagle

top - The Y coordinate of the top of the rectangle

right - The X coordinate of the right side of the rectagle

bottom - The Y coordinate of the bottom of the rectangle

RectF

public RectF(RectF r)

Create a new rectangle, initialized with the values in the specified rectangle (which is left unmodified).

Parameters:

r - The rectangle whose coordinates are copied into the new rectangle.

RectF

public RectF(Rect r)

Method Detail

toString

public String toString()

Description copied from class: Object

Returns a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class Object

Returns:

String a printable representation for the receiver.

isEmpty

public final boolean isEmpty()

Returns true if the rectangle is empty (left >= right or top >= bottom)

width

public final float width()

Returns:

the rectangle's width. This does not check for a valid rectangle (i.e. left <= right) so the result may be negative.

height

public final float height()

Returns:

the rectangle's height. This does not check for a valid rectangle (i.e. top <= bottom) so the result may be negative.

centerX

public final float centerX()

Returns:

the horizontal center of the rectangle. This does not check for a valid rectangle (i.e. left <= right)

centerY

public final float centerY()

Returns:

the vertical center of the rectangle. This does not check for a valid rectangle (i.e. top <= bottom)

setEmpty

public void setEmpty()

Set the rectangle to (0,0,0,0)

set

public void set(float left,
                float top,
                float right,
                float bottom)

Set the rectangle's coordinates to the specified values. Note: no range checking is performed, so it is up to the caller to ensure that left <= right and top <= bottom.

Parameters:

left - The X coordinate of the left side of the rectagle

top - The Y coordinate of the top of the rectangle

right - The X coordinate of the right side of the rectagle

bottom - The Y coordinate of the bottom of the rectangle

set

public void set(RectF src)

Copy the coordinates from src into this rectangle.

Parameters:

src - The rectangle whose coordinates are copied into this rectangle.

set

public void set(Rect src)

Copy the coordinates from src into this rectangle.

Parameters:

src - The rectangle whose coordinates are copied into this rectangle.

offset

public void offset(float dx,
                   float dy)

Offset the rectangle by adding dx to its left and right coordinates, and adding dy to its top and bottom coordinates.

Parameters:

dx - The amount to add to the rectangle's left and right coordinates

dy - The amount to add to the rectangle's top and bottom coordinates

offsetTo

public void offsetTo(float newLeft,
                     float newTop)

Offset the rectangle to a specific (left, top) position, keeping its width and height the same.

Parameters:

newLeft - The new "left" coordinate for the rectangle

newTop - The new "top" coordinate for the rectangle

inset

public void inset(float dx,
                  float dy)

Inset the rectangle by (dx,dy). If dx is positive, then the sides are moved inwards, making the rectangle narrower. If dx is negative, then the sides are moved outwards, making the rectangle wider. The same holds true for dy and the top and bottom.

Parameters:

dx - The amount to add(subtract) from the rectangle's left(right)

dy - The amount to add(subtract) from the rectangle's top(bottom)

contains

public boolean contains(float x,
                        float y)

Returns true if (x,y) is inside the rectangle. The left and top are considered to be inside, while the right and bottom are not. This means that for a x,y to be contained: left <= x < right and top <= y < bottom. An empty rectangle never contains any point.

Parameters:

x - The X coordinate of the point being tested for containment

y - The Y coordinate of the point being tested for containment

Returns:

true iff (x,y) are contained by the rectangle, where containment means left <= x < right and top <= y < bottom

contains

public boolean contains(float left,
                        float top,
                        float right,
                        float bottom)

Returns true iff the 4 specified sides of a rectangle are inside or equal to this rectangle. i.e. is this rectangle a superset of the specified rectangle. An empty rectangle never contains another rectangle.

Parameters:

left - The left side of the rectangle being tested for containment

top - The top of the rectangle being tested for containment

right - The right side of the rectangle being tested for containment

bottom - The bottom of the rectangle being tested for containment

Returns:

true iff the the 4 specified sides of a rectangle are inside or equal to this rectangle

contains

public boolean contains(RectF r)

Returns true iff the specified rectangle r is inside or equal to this rectangle. An empty rectangle never contains another rectangle.

Parameters:

r - The rectangle being tested for containment.

Returns:

true iff the specified rectangle r is inside or equal to this rectangle

intersect

public boolean intersect(float left,
                         float top,
                         float right,
                         float bottom)

If the rectangle specified by left,top,right,bottom intersects this rectangle, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle. No check is performed to see if either rectangle is empty. Note: To just test for intersection, use intersects()

Parameters:

left - The left side of the rectangle being intersected with this rectangle

top - The top of the rectangle being intersected with this rectangle

right - The right side of the rectangle being intersected with this rectangle.

bottom - The bottom of the rectangle being intersected with this rectangle.

Returns:

true if the specified rectangle and this rectangle intersect (and this rectangle is then set to that intersection) else return false and do not change this rectangle.

intersect

public boolean intersect(RectF r)

If the specified rectangle intersects this rectangle, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle. No check is performed to see if either rectangle is empty. To just test for intersection, use intersects()

Parameters:

r - The rectangle being intersected with this rectangle.

Returns:

true if the specified rectangle and this rectangle intersect (and this rectangle is then set to that intersection) else return false and do not change this rectangle.

setIntersect

public boolean setIntersect(RectF a,
                            RectF b)

If rectangles a and b intersect, return true and set this rectangle to that intersection, otherwise return false and do not change this rectangle. No check is performed to see if either rectangle is empty. To just test for intersection, use intersects()

Parameters:

a - The first rectangle being intersected with

b - The second rectangle being intersected with

Returns:

true iff the two specified rectangles intersect. If they do, set this rectangle to that intersection. If they do not, return false and do not change this rectangle.

intersects

public boolean intersects(float left,
                          float top,
                          float right,
                          float bottom)

Returns true if this rectangle intersects the specified rectangle. In no event is this rectangle modified. No check is performed to see if either rectangle is empty. To record the intersection, use intersect() or setIntersect().

Parameters:

left - The left side of the rectangle being tested for intersection

top - The top of the rectangle being tested for intersection

right - The right side of the rectangle being tested for intersection

bottom - The bottom of the rectangle being tested for intersection

Returns:

true iff the specified rectangle intersects this rectangle. In no event is this rectangle modified.

intersects

public static boolean intersects(RectF a,
                                 RectF b)

Returns true iff the two specified rectangles intersect. In no event are either of the rectangles modified. To record the intersection, use intersect() or setIntersect().

Parameters:

a - The first rectangle being tested for intersection

b - The second rectangle being tested for intersection

Returns:

true iff the two specified rectangles intersect. In no event are either of the rectangles modified.

round

public void round(Rect dst)

Set the dst integer Rect by rounding this rectangle's coordinates to their nearest integer values.

roundOut

public void roundOut(Rect dst)

Set the dst integer Rect by rounding "out" this rectangle, choosing the floor of top and left, and the ceiling of right and bottom.

union

public void union(float left,
                  float top,
                  float right,
                  float bottom)

Update this Rect to enclose itself and the specified rectangle. If the specified rectangle is empty, nothing is done. If this rectangle is empty it is set to the specified rectangle.

Parameters:

left - The left edge being unioned with this rectangle

top - The top edge being unioned with this rectangle

right - The right edge being unioned with this rectangle

bottom - The bottom edge being unioned with this rectangle

union

public void union(RectF r)

Update this Rect to enclose itself and the specified rectangle. If the specified rectangle is empty, nothing is done. If this rectangle is empty it is set to the specified rectangle.

Parameters:

r - The rectangle being unioned with this rectangle

union

public void union(float x,
                  float y)

Update this Rect to enclose itself and the [x,y] coordinate. There is no check to see that this rectangle is non-empty.

Parameters:

x - The x coordinate of the point to add to the rectangle

y - The y coordinate of the point to add to the rectangle

sort

public void sort()

Swap top/bottom or left/right if there are flipped (i.e. left > right and/or top > bottom). This can be called if the edges are computed separately, and may have crossed over each other. If the edges are already correct (i.e. left <= right and top <= bottom) then nothing is done.