Android
android.graphics
public final class

android.graphics.Rect

java.lang.Object
android.graphics.Rect Parcelable

Rect holds four integer 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).

Summary

Constants

      Value  
Creator<Rect CREATOR       
Constants inherited from interface android.os.Parcelable

Fields

public      int  bottom   
public      int  left   
public      int  right   
public      int  top   

Public Constructors

            Rect()
Create a new empty Rect.
            Rect(int left, int top, int right, int bottom)
Create a new rectangle with the specified coordinates.
            Rect(Rect r)
Create a new rectangle, initialized with the values in the specified rectangle (which is left unmodified).

Public Methods

    final      int  centerX()
    final      int  centerY()
          boolean  contains(int left, int top, int right, int bottom)
Returns true iff the 4 specified sides of a rectangle are inside or equal to this rectangle.
          boolean  contains(int x, int y)
Returns true if (x,y) is inside the rectangle.
          boolean  contains(Rect r)
Returns true iff the specified rectangle r is inside or equal to this rectangle.
          int  describeContents()
Parcelable interface methods
          boolean  equals(Object obj)
Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
    final      float  exactCenterX()
    final      float  exactCenterY()
    final      int  height()
          void  inset(int dx, int dy)
Inset the rectangle by (dx,dy).
          boolean  intersect(int left, int top, int right, int 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(Rect 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.
      static    boolean  intersects(Rect a, Rect b)
Returns true iff the two specified rectangles intersect.
          boolean  intersects(int left, int top, int right, int bottom)
Returns true if this rectangle intersects the specified rectangle.
    final      boolean  isEmpty()
Returns true if the rectangle is empty (left >= right or top >= bottom)
          void  offset(int dx, int dy)
Offset the rectangle by adding dx to its left and right coordinates, and adding dy to its top and bottom coordinates.
          void  offsetTo(int newLeft, int newTop)
Offset the rectangle to a specific (left, top) position, keeping its width and height the same.
          void  readFromParcel(Parcel in)
Set the rectangle's coordinates from the data stored in the specified parcel.
          void  set(Rect src)
Copy the coordinates from src into this rectangle.
          void  set(int left, int top, int right, int bottom)
Set the rectangle's coordinates to the specified values.
          void  setEmpty()
Set the rectangle to (0,0,0,0)
          boolean  setIntersect(Rect a, Rect 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(int x, int y)
Update this Rect to enclose itself and the [x,y] coordinate.
          void  union(Rect r)
Update this Rect to enclose itself and the specified rectangle.
          void  union(int left, int top, int right, int bottom)
Update this Rect to enclose itself and the specified rectangle.
    final      int  width()
          void  writeToParcel(Parcel out, int flags)
Write this rectangle to the specified parcel.
Methods inherited from class java.lang.Object
Methods inherited from interface android.os.Parcelable

Details

Constants

public static final Creator<Rect> CREATOR

Fields

public int bottom

public int left

public int right

public int top

Public Constructors

public Rect()

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

public Rect(int left, int top, int right, int 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

public Rect(Rect 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.

Public Methods

public final int centerX()

Returns

  • the horizontal center of the rectangle. If the computed value is fractional, this method returns the largest integer that is less than the computed value.

public final int centerY()

Returns

  • the vertical center of the rectangle. If the computed value is fractional, this method returns the largest integer that is less than the computed value.

public boolean contains(int left, int top, int right, int 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

public boolean contains(int x, int 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

public boolean contains(Rect 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

public int describeContents()

Parcelable interface methods

public boolean equals(Object obj)

Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison. The implementation in Object returns true only if the argument is the exact same object as the receiver (==).

Parameters

obj Object the object to compare with this object.

Returns

  • boolean true if the object is the same as this object false if it is different from this object.

public final float exactCenterX()

Returns

  • the exact horizontal center of the rectangle as a float.

public final float exactCenterY()

Returns

  • the exact vertical center of the rectangle as a float.

public final int height()

Returns

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

public void inset(int dx, int 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)

public boolean intersect(int left, int top, int right, int 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.

public boolean intersect(Rect 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.

public static boolean intersects(Rect a, Rect 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.

public boolean intersects(int left, int top, int right, int 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.

public final boolean isEmpty()

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

public void offset(int dx, int 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

public void offsetTo(int newLeft, int 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

public void readFromParcel(Parcel in)

Set the rectangle's coordinates from the data stored in the specified parcel. To write a rectangle to a parcel, call writeToParcel().

Parameters

in The parcel to read the rectangle's coordinates from

public void set(Rect src)

Copy the coordinates from src into this rectangle.

Parameters

src The rectangle whose coordinates are copied into this rectangle.

public void set(int left, int top, int right, int 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

public void setEmpty()

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

public boolean setIntersect(Rect a, Rect 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.

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.

public String toString()

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

Returns

  • String a printable representation for the receiver.

public void union(int x, int 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

public void union(Rect 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

public void union(int left, int top, int right, int 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

public final int width()

Returns

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

public void writeToParcel(Parcel out, int flags)

Write this rectangle to the specified parcel. To restore a rectangle from a parcel, use readFromParcel()

Parameters

out The parcel to write the rectangle's coordinates into
Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:56