AndroidRect

Rect 表示一个矩形, 作为控件信息时则用于表示控件在屏幕的相对位置及空间范围, 又称 控件矩形.

let bounds = pickup(/.+/, 'bounds');
console.log(`${bounds.centerX()}, ${bounds.centerY()}`);

常见相关方法或属性:

注: 本章节仅列出部分属性或方法.

android.graphics.Rect

[C] android.graphics.Rect

[c] (left, top, right, bottom)

left { number } - 矩形左边界 X 坐标
top { number } - 矩形上边界 Y 坐标
right { number } - 矩形右边界 X 坐标
bottom { number } - 矩形下边界 Y 坐标
returns { android.graphics.Rect }

生成一个矩形.

let rect = new android.graphics.Rect(10, 20, 80, 90);
console.log(rect); // Rect(10, 20 - 80, 90)

如果坐标值为浮点数, 将做向下取整处理:

let rect = new android.graphics.Rect(10.2, 20.7, 80.1, 90.92);
console.log(rect); // Rect(10, 20 - 80, 90)

坐标值可以为 0 或负数:

let rect = new android.graphics.Rect(0, 0, -80, -90);
console.log(rect); // Rect(0, 0 - -80, -90)

[c] ()

returns { android.graphics.Rect }

生成一个空矩形.

let rect = new android.graphics.Rect();
console.log(rect); // Rect(0, 0 - 0, 0)

[c] (rect)

rect { android.graphics.Rect } - 参照矩形
returns { android.graphics.Rect }

生成一个新矩形, 并按照参照矩形的参数初始化.

let rectA = new android.graphics.Rect(10, 20, 80, 90);
let rectB = new android.graphics.Rect(rectA);
console.log(rectB); // Rect(10, 20 - 80, 90)
rectB.top = 1;
rectB.bottom = 0;
console.log(rectB); // Rect(10, 1 - 80, 0)
console.log(rectA); // Rect(10, 20 - 80, 90)

[p#] left

{ number }

矩形左边界 X 坐标.

如: Rect(180, 440, 750, 1200) 表示矩形左边界距屏幕左边缘 180 像素.

[p#] top

{ number }

矩形上边界 Y 坐标.

如: Rect(180, 440, 750, 1200) 表示矩形上边界距屏幕上边缘 440 像素.

[p#] right

{ number }

矩形右边界 X 坐标.

如: Rect(180, 440, 750, 1200) 表示矩形右边界距屏幕左边缘 750 像素.

[p#] bottom

{ number }

矩形下边界 Y 坐标.

如: Rect(180, 440, 750, 1200) 表示矩形下边界距屏幕上边缘 1200 像素.

[m#] width

width()

returns { number }

矩形宽度.

let rect = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rect.width()); // 570

宽度可能为 0 或负数:

let rectA = new android.graphics.Rect(0, 440, 0, 1200);
console.log(rectA.width()); // 0
let rectB = new android.graphics.Rect(30, 440, 10, 1200);
console.log(rectB.width()); // -20

[m#] height

height()

returns { number }

矩形高度.

let rect = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rect.height()); // 760

高度可能为 0 或负数:

let rectA = new android.graphics.Rect(180, 1200, 750, 1200);
console.log(rectA.height()); // 0
let rectB = new android.graphics.Rect(180, 40, 750, 10);
console.log(rectB.height()); // -30

[m#] centerX

centerX()

returns { number }

矩形中点 X 坐标 (向下取整).

let rectA = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rectA.centerX()); // 465

let rectB = new android.graphics.Rect(100, 200, 101, 201);
console.log(rectB.centerX()); // 100

[m#] centerY

centerY()

returns { number }

矩形中点 Y 坐标 (向下取整).

let rectA = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rectA.centerY()); // 820

let rectB = new android.graphics.Rect(100, 200, 101, 201);
console.log(rectB.centerY()); // 200

[m#] exactCenterX

exactCenterX()

returns { number }

矩形中点 X 坐标 (浮点数).

let rectA = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rectA.exactCenterX()); // 465

let rectB = new android.graphics.Rect(100, 200, 101, 201);
console.log(rectB.exactCenterX()); // 100.5

[m#] exactCenterY

exactCenterY()

returns { number }

矩形中点 Y 坐标 (浮点数).

let rectA = new android.graphics.Rect(180, 440, 750, 1200);
console.log(rectA.exactCenterY()); // 820

let rectB = new android.graphics.Rect(100, 200, 101, 201);
console.log(rectB.exactCenterY()); // 200.5

[m#] contains

contains(rect)

rect { android.graphics.Rect } - 参照矩形
returns { boolean }

返回是否包含另一个矩形.
参照矩形的所有边均在当前矩形内 (包含边重叠情况) 则满足包含条件.
空矩形与任何矩形不存在包含关系.

let rectThis = new android.graphics.Rect(180, 440, 750, 1200);

let rectRefA = new android.graphics.Rect(rectThis);
console.log(rectThis.contains(rectRefA)); // true

let rectRefB = new android.graphics.Rect(200, 440, 750, 1200);
console.log(rectThis.contains(rectRefB)); // true

let rectRefC = new android.graphics.Rect(); /* 空矩形. */
console.log(rectThis.contains(rectRefC)); // false

[m#] intersect

intersect(rect)

rect { android.graphics.Rect } - 参照矩形
returns { boolean }

返回是否与参展矩形相交 (不包括边界或点重叠的情况).
如果相交, 则返回 true, 且当前矩形被设置为相交部分的矩形.

let rectThis = new android.graphics.Rect(0, 0, 600, 600);
let rectRef = new android.graphics.Rect(200, 0, 800, 800);

console.log(rectThis.intersect(rectRef)); // true

/* rectThis 被修改. */
console.log(rectThis); // Rect(200, 0 - 600, 600)

如果不相交, 则返回 false, 当前矩形不会被修改:

let rectThis = new android.graphics.Rect(0, 0, 100, 100);
let rectRef = new android.graphics.Rect(100, 0, 800, 800);

console.log(rectThis.intersect(rectRef)); // false

/* rectThis 保持原来的值. */
console.log(rectThis); // Rect(0, 0 - 100, 100)

空矩形与任意矩形不相交:

let rectThis = new android.graphics.Rect(0, 0, 100, 100);
let rectRef = new android.graphics.Rect();
console.log(rectThis.intersect(rectRef)); // false

[m] intersects

intersects(rectA, rectB)

rect { android.graphics.Rect } - 参照矩形
returns { boolean }

返回是否和另一个长方形相交.

此方法近判断是否相交, 不改变任何矩形:

let rectA = new android.graphics.Rect(0, 0, 600, 600);
let rectB = new android.graphics.Rect(200, 0, 800, 800);

console.log(android.graphics.Rect.intersects(rectA, rectB)); // true

/* rectA 和 refB 均保持原来的值. */
console.log(rectA); // Rect(0, 0 - 600, 600)
console.log(rectB); // Rect(200, 0 - 800, 800)

需额外留意 intersects 与 intersect 的区别:

[m#] intersect 为实例方法, rectA.intersect(rectB) 需传入一个参数, 当相交时 rectA 会被改变, 返回结果为 "是否相交".
[m] intersects 为静态方法, Rect.intersects(rectA, rectB) 需传入两个参数, 且不改变任何矩形, 仅返回 "是否相交" 结果.