public final class Rect
extends Object
implements Parcelable
java.lang.Object | |
↳ | android.graphics.Rect |
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).
Note that the right and bottom coordinates are exclusive. This means a Rect being drawn untransformed onto a Canvas
will draw into the column and row described by its left and top coordinates, but not those of its bottom and right.
Inherited constants |
---|
![]() android.os.Parcelable
|
Fields |
|
---|---|
public static final Creator<Rect> |
CREATOR
|
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(Rect r) Returns true iff the specified rectangle r is inside or equal to this rectangle. |
boolean |
contains(int x, int y) Returns true if (x,y) is inside the rectangle. |
int |
describeContents() Parcelable interface methods |
boolean |
equals(Object o) Indicates whether some other object is "equal to" this one. |
final float |
exactCenterX() |
final float |
exactCenterY() |
String |
flattenToString() Return a string representation of the rectangle in a well-defined format. |
int |
hashCode() Returns a hash code value for the object. |
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. |
boolean |
intersects(int left, int top, int right, int bottom) Returns true if this rectangle intersects the specified rectangle. |
static boolean |
intersects(Rect a, Rect b) Returns true iff the two specified rectangles intersect. |
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(int left, int top, int right, int bottom) Set the rectangle's coordinates to the specified values. |
void |
set(Rect src) Copy the coordinates from src into this rectangle. |
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 |
toShortString() Return a string representation of the rectangle in a compact form. |
String |
toString() Returns a string representation of the object. |
static Rect |
unflattenFromString(String str) Returns a Rect from a string of the form returned by |
void |
union(int left, int top, int right, int bottom) Update this Rect to enclose itself and the specified rectangle. |
void |
union(Rect r) Update this Rect to enclose itself and the specified rectangle. |
void |
union(int x, int y) Update this Rect to enclose itself and the [x,y] coordinate. |
final int |
width() |
void |
writeToParcel(Parcel out, int flags) Write this rectangle to the specified parcel. |
Inherited methods |
|
---|---|
![]() java.lang.Object
|
|
![]() android.os.Parcelable
|
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 |
int : The X coordinate of the left side of the rectangle |
top |
int : The Y coordinate of the top of the rectangle |
right |
int : The X coordinate of the right side of the rectangle |
bottom |
int : The Y coordinate of the bottom of the rectangle |
Rect (Rect r)
Create a new rectangle, initialized with the values in the specified rectangle (which is left unmodified).
Parameters | |
---|---|
r |
Rect : The rectangle whose coordinates are copied into the new rectangle. |
int centerX ()
Returns | |
---|---|
int |
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. |
int centerY ()
Returns | |
---|---|
int |
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. |
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 |
int : The left side of the rectangle being tested for containment |
top |
int : The top of the rectangle being tested for containment |
right |
int : The right side of the rectangle being tested for containment |
bottom |
int : The bottom of the rectangle being tested for containment |
Returns | |
---|---|
boolean |
true iff the the 4 specified sides of a rectangle are inside or equal to this rectangle |
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 |
Rect : The rectangle being tested for containment. |
Returns | |
---|---|
boolean |
true iff the specified rectangle r is inside or equal to this rectangle |
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 |
int : The X coordinate of the point being tested for containment |
y |
int : The Y coordinate of the point being tested for containment |
Returns | |
---|---|
boolean |
true iff (x,y) are contained by the rectangle, where containment means left <= x < right and top <= y < bottom |
int describeContents ()
Parcelable interface methods
Returns | |
---|---|
int |
a bitmask indicating the set of special object types marshaled by this Parcelable object instance. |
boolean equals (Object o)
Indicates whether some other object is "equal to" this one.
The equals
method implements an equivalence relation on non-null object references:
x
, x.equals(x)
should return true
. x
and y
, x.equals(y)
should return true
if and only if y.equals(x)
returns true
. x
, y
, and z
, if x.equals(y)
returns true
and y.equals(z)
returns true
, then x.equals(z)
should return true
. x
and y
, multiple invocations of x.equals(y)
consistently return true
or consistently return false
, provided no information used in equals
comparisons on the objects is modified. x
, x.equals(null)
should return false
. The equals
method for class Object
implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x
and y
, this method returns true
if and only if x
and y
refer to the same object (x == y
has the value true
).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the general contract for the hashCode
method, which states that equal objects must have equal hash codes.
Parameters | |
---|---|
o |
Object : the reference object with which to compare. |
Returns | |
---|---|
boolean |
true if this object is the same as the obj argument; false otherwise. |
float exactCenterX ()
Returns | |
---|---|
float |
the exact horizontal center of the rectangle as a float. |
float exactCenterY ()
Returns | |
---|---|
float |
the exact vertical center of the rectangle as a float. |
String flattenToString ()
Return a string representation of the rectangle in a well-defined format.
You can later recover the Rect from this string through unflattenFromString(String)
.
Returns | |
---|---|
String |
Returns a new String of the form "left top right bottom" |
int hashCode ()
Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap
.
The general contract of hashCode
is:
hashCode
method must consistently return the same integer, provided no information used in equals
comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. equals(Object)
method, then calling the hashCode
method on each of the two objects must produce the same integer result. equals(java.lang.Object)
method, then calling the hashCode
method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. As much as is reasonably practical, the hashCode method defined by class Object
does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
Returns | |
---|---|
int |
a hash code value for this object. |
int height ()
Returns | |
---|---|
int |
the rectangle's height. This does not check for a valid rectangle (i.e. top <= bottom) so the result may be negative. |
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 |
int : The amount to add(subtract) from the rectangle's left(right) |
dy |
int : The amount to add(subtract) from the rectangle's top(bottom) |
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(Rect, Rect)
.
Parameters | |
---|---|
left |
int : The left side of the rectangle being intersected with this rectangle |
top |
int : The top of the rectangle being intersected with this rectangle |
right |
int : The right side of the rectangle being intersected with this rectangle. |
bottom |
int : The bottom of the rectangle being intersected with this rectangle. |
Returns | |
---|---|
boolean |
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. |
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 |
Rect : The rectangle being intersected with this rectangle. |
Returns | |
---|---|
boolean |
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. |
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 |
int : The left side of the rectangle being tested for intersection |
top |
int : The top of the rectangle being tested for intersection |
right |
int : The right side of the rectangle being tested for intersection |
bottom |
int : The bottom of the rectangle being tested for intersection |
Returns | |
---|---|
boolean |
true iff the specified rectangle intersects this rectangle. In no event is this rectangle modified. |
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(Rect)
or setIntersect(Rect, Rect)
.
Parameters | |
---|---|
a |
Rect : The first rectangle being tested for intersection |
b |
Rect : The second rectangle being tested for intersection |
Returns | |
---|---|
boolean |
true iff the two specified rectangles intersect. In no event are either of the rectangles modified. |
boolean isEmpty ()
Returns true if the rectangle is empty (left >= right or top >= bottom)
Returns | |
---|---|
boolean |
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 |
int : The amount to add to the rectangle's left and right coordinates |
dy |
int : The amount to add to the rectangle's 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.
Parameters | |
---|---|
newLeft |
int : The new "left" coordinate for the rectangle |
newTop |
int : The new "top" coordinate for the rectangle |
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 |
Parcel : The parcel to read the rectangle's coordinates from |
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 |
int : The X coordinate of the left side of the rectangle |
top |
int : The Y coordinate of the top of the rectangle |
right |
int : The X coordinate of the right side of the rectangle |
bottom |
int : The Y coordinate of the bottom of the rectangle |
void set (Rect src)
Copy the coordinates from src into this rectangle.
Parameters | |
---|---|
src |
Rect : The rectangle whose coordinates are copied into this rectangle. |
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 |
Rect : The first rectangle being intersected with |
b |
Rect : The second rectangle being intersected with |
Returns | |
---|---|
boolean |
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. |
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.
String toShortString ()
Return a string representation of the rectangle in a compact form.
Returns | |
---|---|
String |
String toString ()
Returns a string representation of the object. In general, the toString
method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@
', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
Returns | |
---|---|
String |
a string representation of the object. |
Rect unflattenFromString (String str)
Returns a Rect from a string of the form returned by flattenToString()
, or null if the string is not of that form.
Parameters | |
---|---|
str |
String
|
Returns | |
---|---|
Rect |
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 |
int : The left edge being unioned with this rectangle |
top |
int : The top edge being unioned with this rectangle |
right |
int : The right edge being unioned with this rectangle |
bottom |
int : The bottom edge being unioned with this rectangle |
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 |
Rect : The rectangle being unioned with this rectangle |
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 |
int : The x coordinate of the point to add to the rectangle |
y |
int : The y coordinate of the point to add to the rectangle |
int width ()
Returns | |
---|---|
int |
the rectangle's width. This does not check for a valid rectangle (i.e. left <= right) so the result may be negative. |
void writeToParcel (Parcel out, int flags)
Write this rectangle to the specified parcel. To restore a rectangle from a parcel, use readFromParcel()
Parameters | |
---|---|
out |
Parcel : The parcel to write the rectangle's coordinates into |
flags |
int : Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE . |