BaseBottomSheetDialogFragment.kt

abstract class BaseBottomSheetDialogFragment : BottomSheetDialogFragment() {

    @LayoutRes
    protected abstract fun layoutRes(): Int

    protected abstract fun onViewCreated()

    private var sheetBehavior: BottomSheetBehavior<*>? = null
    private var peekHeight = 0
    private var expandedOffset = 0
    private var halfExpandedEnabled = false
    private var isFitToContents = true
    private var isDraggable = true
    private var hideable = true
    private var cancelable = true
    private var canceledOnTouchOutside = true
    private var skipCollapsed = true
    private var fullScreen = false
    private var dimAmount = 0.6f //Default dim amount

    private var bottomSheetCallback: BottomSheetBehavior.BottomSheetCallback? = null

    fun setFullScreen(fullScreen: Boolean) {
        this.fullScreen = fullScreen
    }

    fun setPeekHeight(peekHeight: Int) {
        this.peekHeight = peekHeight
    }

    fun setExpandedOffset(expandedOffset: Int) {
        this.expandedOffset = expandedOffset
    }

    fun setHalfExpandedEnabled(halfExpandedEnabled: Boolean) {
        this.halfExpandedEnabled = halfExpandedEnabled
    }

    fun setDimAmount(@FloatRange dimAmount: Float) {
        this.dimAmount = dimAmount
    }

    fun setFitToContents(fitToContents: Boolean) {
        isFitToContents = fitToContents
    }

    fun setHideable(hideable: Boolean) {
        this.hideable = hideable
    }

    fun setDraggable(draggable: Boolean) {
        isDraggable = draggable
    }

    override fun setCancelable(cancelable: Boolean) {
        this.cancelable = cancelable
    }

    fun setCanceledOnTouchOutside(canceledOnTouchOutside: Boolean) {
        this.canceledOnTouchOutside = canceledOnTouchOutside
    }

    fun setSkipCollapsed(skipCollapsed: Boolean) {
        this.skipCollapsed = skipCollapsed
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(layoutRes(), container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        onViewCreated()
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        val dialog = dialog as BottomSheetDialog?
        if (dialog != null) {
            if (dimAmount != 0.6f) {
                val window = dialog.window
                val windowParams = window?.attributes
                windowParams?.dimAmount = dimAmount
                Log.d("DIM", "amount: " + windowParams?.dimAmount)
                windowParams?.flags =
                    windowParams?.flags?.or(WindowManager.LayoutParams.FLAG_DIM_BEHIND)
                window?.attributes = windowParams
            }
            dialog.setCancelable(cancelable)
            dialog.setCanceledOnTouchOutside(canceledOnTouchOutside)
            dialog.setOnShowListener(DialogInterface.OnShowListener {
                sheetBehavior?.state = BottomSheetBehavior.STATE_EXPANDED
                bottomSheetListener?.onShow()
            })
            dialog.setOnCancelListener(DialogInterface.OnCancelListener {
                dismiss()
                dialog.dismiss()
                bottomSheetListener?.onHide()
            })
            dialog.setOnDismissListener(DialogInterface.OnDismissListener {
                dismiss()
                dialog.dismiss()
                bottomSheetListener?.onHide()
            })
            val bottomSheetView =
                dialog.findViewById<FrameLayout>(com.google.android.material.R.id.design_bottom_sheet)
            if (bottomSheetView != null) {
                if (bottomSheetView.layoutParams != null && fullScreen) {
                    bottomSheetView.layoutParams.height = ViewGroup.LayoutParams.MATCH_PARENT
                }
                sheetBehavior = BottomSheetBehavior.from(bottomSheetView)
                if (halfExpandedEnabled) {
                    sheetBehavior?.halfExpandedRatio = 0.6f
                    sheetBehavior?.setFitToContents(false)
                } else {
                    sheetBehavior?.setFitToContents(isFitToContents)
                }
                if (peekHeight != 0) {
                    sheetBehavior?.peekHeight = peekHeight
                }
                if (expandedOffset != 0) {
                    sheetBehavior?.setExpandedOffset(expandedOffset)
                }
                sheetBehavior?.isHideable = hideable
                sheetBehavior?.skipCollapsed = skipCollapsed
                sheetBehavior?.addBottomSheetCallback(object :
                    BottomSheetBehavior.BottomSheetCallback() {
                    override fun onStateChanged(bottomSheet: View, newState: Int) {
                        bottomSheetCallback?.onStateChanged(bottomSheet, newState)
                        if (newState == BottomSheetBehavior.STATE_HIDDEN) {
                            bottomSheetListener?.onHide()
                            dismiss()
                            dialog.dismiss()
                        }
                    }

                    override fun onSlide(bottomSheet: View, slideOffset: Float) {
                        bottomSheetCallback?.onSlide(bottomSheet, slideOffset)
                    }
                })
            }
        }
    }

    fun hideUponCall() {
        if (sheetBehavior != null) {
            sheetBehavior!!.state = BottomSheetBehavior.STATE_HIDDEN
            if (bottomSheetListener != null) {
                bottomSheetListener!!.onHide()
            }
            dismiss()
            if (dialog != null) {
                val dialog = dialog as BottomSheetDialog?
                dialog!!.dismiss()
            }
        }
    }

    fun hideUponCall(changed: Boolean) {
        if (sheetBehavior != null) {
            sheetBehavior!!.state = BottomSheetBehavior.STATE_HIDDEN
            if (bottomSheetListener != null) {
                bottomSheetListener!!.onHide(changed)
            }
            dismiss()
        }
    }

    private var bottomSheetListener: BottomSheetListener? = null
    fun setBottomSheetListener(bottomSheetListener: BottomSheetListener?) {
        this.bottomSheetListener = bottomSheetListener
    }

    class SimpleBottomSheetListener : BottomSheetListener {
        override fun onShow() {}
        override fun onHide() {}
        override fun onHide(changed: Boolean) {}
    }

    interface BottomSheetListener {
        fun onShow()
        fun onHide()
        fun onHide(changed: Boolean)
    }

}