Android 自定义图片地图坐标功能的实现
一、前言
最近项目要求实现一个在自定义地图图片上添加坐标信息的功能，类似于在图片做标注的功能。如下图所示。坐标的位置是相对于图片宽高的百分比
二、思路
改功能主要分为三个视图，1.继承FrameLayout作为父容器；2.添加一个铺满父布局的ImageView显示地图图片；3.动态添加自定义坐标视图
三、代码实现
1. 自定义坐标视图
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/iv_sign"
android:layout_width="20dp"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:src="@mipmap/dot2"
app:layout_constraintEnd_toStartOf="@+id/tv_sign_name"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/tv_sign_name"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:background="@color/white"
android:text="美食城"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/tv_sign_state"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:background="@color/teal_200"
android:text="正常"
android:textColor="@color/white"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@+id/tv_sign_name"
app:layout_constraintTop_toBottomOf="@+id/tv_sign_name" />
</androidx.constraintlayout.widget.ConstraintLayout>
class SignView : ConstraintLayout {
private val TAG = SignView::class.java.simpleName
private var view: View
private var signIv: ImageView
private var signNameTv: TextView
private var signStateTv: TextView
constructor(context: Context) : super(context)
constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
constructor(context: Context, attrs: AttributeSet?, @AttrRes defStyleAttr: Int) : super(
context,
attrs,
defStyleAttr
)
init {
view = LayoutInflater.from(context).inflate(R.layout.sign_view, this, true)
signIv = view.findViewById(R.id.iv_sign)
signNameTv = view.findViewById(R.id.tv_sign_name)
signStateTv = view.findViewById(R.id.tv_sign_state)
}
/**
* 设置坐标信息
* @param signBean SignBean
*/
fun setData(signBean: SignBean) {
signNameTv.text = signBean.name
signStateTv.text = signBean.state
}
/**
* 计算坐标图标在整个视图的偏移量
* @return IntArray
*/
fun getSignOffset(): IntArray {
val w = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
val h = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)
signIv.measure(w, h)
val offset = IntArray(2)
val signImageWidth = signIv.measuredWidth
val signImageHeight = signIv.measuredHeight
offset[0] = signImageWidth / 2
offset[1] = 20 + signImageHeight - offset[0]
Log.d(TAG, "getSignOffset: x:${offset[0]}, y:${offset[1]}")
return offset
}
}
自定义的坐标视图是一个组合的控件，主要是要计算出坐标图片在整个控件的偏移量
2. 父容器
class MapView : FrameLayout {
private val TAG = MapView::class.java.simpleName
//地图图片
private var mapImage = ImageView(context)
private var mapWidth = 0
private var mapHeight = 0
private var mapLeft = 0
private var mapTop = 0
private var signBeanList = listOf<SignBean>()
private var signOffsetList = mutableListOf<IntArray>()
private var signViewList = mutableListOf<SignView>()
private var capturedViewIndex = 0
private val mDragger: ViewDragHelper =
ViewDragHelper.create(this, 1.0f, object : ViewDragHelper.Callback() {
override fun tryCaptureView(child: View, pointerId: Int): Boolean {
return child != mapImage
}
override fun onViewCaptured(capturedChild: View, activePointerId: Int) {
signViewList.forEachIndexed { index, signView ->
if (signView == capturedChild) {
capturedViewIndex = index
return@forEachIndexed
}
}
}
override fun onViewPositionChanged(
changedView: View,
left: Int,
top: Int,
dx: Int,
dy: Int
) {
signOffsetList[capturedViewIndex][0] += dx
signOffsetList[capturedViewIndex][1] += dy
}
override fun clampViewPositionHorizontal(child: View, left: Int, dx: Int): Int {
val move = if (left <= mapLeft)
mapLeft
else if (left >= mapWidth + mapLeft)
mapWidth + mapLeft
else
left
return move
}
override fun clampViewPositionVertical(child: View, top: Int, dy: Int): Int {
val move = if (top <= mapTop)
mapTop
else if (top >= mapHeight + mapTop)
mapHeight + mapLeft
else
top
return move
}
})
constructor(context: Context) : super(context)
constructor(context: Context, attrs: AttributeSet?) : this(context, attrs, 0)
constructor(context: Context, attrs: AttributeSet?, @AttrRes defStyleAttr: Int) : this(
context,
attrs,
defStyleAttr,
0
)
constructor(
context: Context, attrs: AttributeSet?,
@AttrRes defStyleAttr: Int, @StyleRes defStyleRes: Int
) : super(context, attrs, defStyleAttr, defStyleRes)
/**
* 添加地图图片
* @param resId Int
*/
fun setMapImage(@DrawableRes resId: Int) {
removeAllViews()
mapImage.setImageResource(resId)
addView(mapImage)
}
/**
* 设置坐标列表
* @param list List<SignBean>
*/
fun setSignData(list: List<SignBean>) {
val mapOffset = getBitmapOffset(mapImage, true)
mapLeft = mapOffset[0]
mapTop = mapOffset[1]
mapWidth = mapImage.width - mapLeft * 2
mapHeight = mapImage.height - mapTop * 2
var signOffset = IntArray(2)
var boolean = true
Log.d(TAG, "mapWidth:$mapWidth, mapHeight:$mapHeight, mapLeft:$mapLeft, mapTop:$mapTop")
signBeanList = list
removeViews(1, childCount - 1)
signViewList.clear()
signOffsetList.clear()
list.forEach {
val signView = SignView(context).apply {
setData(it)
}
// 只需要计算一次
if (boolean) {
boolean = false
signOffset = signView.getSignOffset()
}
signView.layoutParams = getParams(it, signOffset)
addView(signView)
signViewList.add(signView)
signOffsetList.add(intArrayOf((it.x * mapWidth).toInt(), (it.y * mapHeight).toInt()))
}
}
/**
* 获取移动后的坐标信息
* @return List<SignBean>
*/
fun getMoveSignData(): List<SignBean> {
val data = mutableListOf<SignBean>()
signOffsetList.forEachIndexed { index, ints ->
val signBean = signBeanList[index]
data.add(
SignBean(
signBean.name,
signBean.state,
ints[0] / mapWidth.toFloat(),
ints[1] / mapHeight.toFloat()
)
)
}
return data
}
/**
* 计算坐标位置
* @param signBean SignBean
* @return LayoutParams
*/
private fun getParams(signBean: SignBean, signOffset: IntArray): LayoutParams {
val params = LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)
params.setMargins(
(signBean.x * mapWidth + mapLeft - signOffset[0]).toInt(),
(signBean.y * mapHeight + mapTop - signOffset[1]).toInt(),
0,
0
)
return params
}
/**
* 计算图像在ImageView的位移量
* @param img ImageView
* @param includeLayout Boolean
* @return IntArray?
*/
private fun getBitmapOffset(img: ImageView, includeLayout: Boolean): IntArray {
val offset = IntArray(2)
val values = FloatArray(9)
val m: Matrix = img.imageMatrix
m.getValues(values)
offset[0] = values[2].toInt()
offset[1] = values[5].toInt()
if (includeLayout) {
val lp = img.layoutParams as MarginLayoutParams
offset[0] += img.paddingLeft + lp.leftMargin
offset[1] += img.paddingTop + lp.topMargin
}
return offset
}
override fun onInterceptTouchEvent(event: MotionEvent): Boolean {
return mDragger.shouldInterceptTouchEvent(event)
}
override fun onTouchEvent(event: MotionEvent): Boolean {
mDragger.processTouchEvent(event)
return true
}
}
父容器中要注意的是由于图片不拉伸，所以会出现图片不会完成铺满ImageView，会有黑边。所以要计算出实际图片显示的大小。
3. Activity
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<com.itc.floatparade.MapView
android:id="@+id/map"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="12dp"
android:background="@color/black"
app:layout_constraintBottom_toTopOf="@+id/tv_add_sign"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/tv_add_sign"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="25dp"
android:layout_marginBottom="12dp"
android:text="添加坐标"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<Button
android:id="@+id/btn_get_sign"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="25dp"
android:text="获取坐标"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/map" />
<TextView
android:id="@+id/tv_sign_list"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginEnd="8dp"
android:text=""
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/btn_get_sign"
app:layout_constraintStart_toEndOf="@+id/tv_add_sign"
app:layout_constraintTop_toBottomOf="@+id/map" />
</androidx.constraintlayout.widget.ConstraintLayout>
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
binding.map.setMapImage(R.mipmap.map)
binding.tvAddSign.setOnClickListener {
val list = mutableListOf<SignBean>()
list.add(SignBean("美食城", "正常", 0.2f, 0.4f))
list.add(SignBean("恐龙危机", "正常", 0.5f, 0.5f))
list.add(SignBean("海盗船", "正常", 0.7f, 0.6f))
list.add(SignBean("魔法城堡", "正常", 0.4f, 0.8f))
binding.map.setSignData(list)
}
binding.btnGetSign.setOnClickListener {
val list = binding.map.getMoveSignData()
binding.tvSignList.text = list.toString()
}
}
}
完整代码：https://github.com/MattLjp/FloatParade