Android畫板開發(fā)之添加文本文字

companion object {
    const val EDIT_MODE_PEN = 0x1L    //畫筆模式
    const val EDIT_MODE_ERASER = 0x2L  //橡皮擦模式
    const val EDIT_MODE_TEXT = 0x3L  //文字模式

  }

  @Retention(AnnotationRetention.SOURCE)
  @IntDef(EDIT_MODE_PEN, EDIT_MODE_ERASER, EDIT_MODE_TEXT)
  annotation class EditMode

  /**
   * 設(shè)置畫筆模式
   */
  fun setModel(@EditMode model: Long) {
    mMode = model
    when (model) {
      EDIT_MODE_PEN -> {
        //畫線
        mPaint.xfermode = null
        mPaint.style = Paint.Style.STROKE
      }
      EDIT_MODE_ERASER -> {
        mPaint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR)

      }
      EDIT_MODE_TEXT -> {
        mPaint.style = Paint.Style.FILL
      }
    }
  }

StaticLayout.Builder builder = StaticLayout.Builder.obtain(mHint, 0,
     mHint.length(), mTextPaint, hintWidth)
     .setAlignment(alignment)
     .setTextDirection(mTextDir)
     .setLineSpacing(mSpacingAdd, mSpacingMult)
     .setIncludePad(mIncludePad)
     .setBreakStrategy(mBreakStrategy)
     .setHyphenationFrequency(mHyphenationFrequency);

public StaticLayout(CharSequence source, //字符串
   TextPaint paint, //畫筆對(duì)象
   int width,  //layout的寬度，字符串超出寬度時(shí)自動(dòng)換行。
   Layout.Alignment align, //layout的對(duì)其方式，有ALIGN_CENTER， ALIGN_NORMAL， ALIGN_OPPOSITE 三種。
   float spacingmult,  //相對(duì)行間距，相對(duì)字體大小，1.5f表示行間距為1.5倍的字體高度。
   float spacingadd,  //在基礎(chǔ)行距上添加多少
   boolean includepad)  //文本頂部和底部是否留白

data class PaintBean(
    var mPaint: Paint,  //保存畫筆
    var mPath: Path?,     //保存路徑
    var mText: String,    //文本
    var mWidth: Int,
    var mOffX: Float,
    var mOffY: Float,
    private @TPTextView.EditMode var mMode:Long
) {

  constructor(mPaint: Paint, mPath: Path) : this(mPaint,mPath,"",0,0f,0f,TPTextView.EDIT_MODE_PEN)

  /**
   * 撤銷和反撤銷之后 重新繪制
   * @param canvas 繪制的畫布
   */
  fun draw(canvas: Canvas){

    when(mMode){

      TPTextView.EDIT_MODE_TEXT -> {

        if(!TextUtils.isEmpty(mText)){
          //調(diào)節(jié)畫布起始坐標(biāo)進(jìn)行繪制
          canvas.translate(mOffX,mOffY)
          //利用staticLayout生成文字，不然不能換行
          val staticLayout = StaticLayout(mText,mPaint as TextPaint,mWidth, Layout.Alignment.ALIGN_NORMAL, 1.0f, 0.0f, false)
          staticLayout.draw(canvas)
          //Log.e("@@","長(zhǎng)度："+staticLayout.width)
          //canvas.drawText(mText,mTextOffX,mTextOffY,mPaint)
          //恢復(fù)畫布坐標(biāo)
          canvas.translate(-mOffX,-mOffY)

        }

      }
      else -> {
        canvas.drawPath(mPath,mPaint)
      }

    }

  }

  fun getMode():Long = mMode

}

private var mTextPopup: PopupWindow? = null
private var mTextView: EditText? = null

  /**
   * 顯示popup文本輸入彈窗
   */
  private fun showTextPopup() {

    if (null == mTextPopup) {
      mTextView = EditText(context)
      mTextView?.hint = "文字"

      mTextPopup = PopupWindow(mTextView,
          WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT,
          true)
      mTextPopup?.setOnDismissListener {
        if (!TextUtils.isEmpty(mTextView?.text)) {
          //添加到列表
          mPaintedList.add(
              PaintBean(TextPaint(mPaint), null, mTextView?.text.toString(), (width - preX).toInt(),preX,preY - mTextView!!.height / 2, EDIT_MODE_TEXT))

          invalidate()
        }
      }
      //讓popup顯示在軟鍵盤上面
      mTextPopup?.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE
    }

    mTextView?.requestFocus()

    //自動(dòng)彈出軟鍵盤，會(huì)導(dǎo)致布局變化，重測(cè)量、繪制
    val imm = context.getSystemService(Service.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS)


    mTextPopup?.showAtLocation(this, Gravity.TOP and Gravity.LEFT, preX.toInt(), preY.toInt()+mTextView!!.height)

  }

@SuppressLint("ClickableViewAccessibility")
  override fun onTouchEvent(event: MotionEvent): Boolean {

    when (event.action) {
      MotionEvent.ACTION_DOWN -> { //手指按下的時(shí)候
        //記錄上次觸摸的坐標(biāo)，注意ACTION_DOWN方法只會(huì)執(zhí)行一次
        preX = event.x
        preY = event.y
        when (mMode) {

          EDIT_MODE_TEXT -> {
            //彈出popupWidnwo輸入text
            showTextPopup()
            //文字在隱藏的時(shí)候添加到list
          }
          else -> {
            //將起始點(diǎn)移動(dòng)到當(dāng)前坐標(biāo)
            mPath.moveTo(event.x, event.y)
            mPaintedList.add(PaintBean(Paint(mPaint), Path(mPath)))
          }
        }

      }
      MotionEvent.ACTION_MOVE -> { //手指移動(dòng)的時(shí)候
        when (mMode) {
          EDIT_MODE_TEXT -> {

          }
          else -> {
            //繪制圓滑曲線，即貝塞爾曲線,貝塞爾曲線這個(gè)知識(shí)自行了解
            mPaintedList.get(mPaintedList.size - 1).mPath?.quadTo(preX, preY, event.x, event.y)
            preX = event.x
            preY = event.y
            //重新繪制，會(huì)調(diào)用onDraw方法
            invalidate()
          }

        }
      }
      MotionEvent.ACTION_UP -> {}
    }

    return true
  }

@SuppressLint("DrawAllocation")
  override fun onDraw(canvas: Canvas) {
    super.onDraw(canvas)

    //超出緩存的就固化到緩存bitmap
    while (mPaintedList.size > PAINT_RECORED_NUM) {
      val paint = mPaintedList.removeAt(0)
      paint.draw(mHoldCanvas!!)
    }

    //繪制固化的內(nèi)容到緩存Canvas
    mBufferCanvas?.drawBitmap(mHoldBitmap, 0f, 0f, null)

    //繪制記錄的畫筆
    for (paint in mPaintedList) {
      paint.draw(mBufferCanvas!!)
    }

    //畫出緩存bitmap的內(nèi)容
    canvas.drawBitmap(mBufferBitmap, 0f, 0f, null)

  }