CODEWITHSUNDEEP
androidkotlinkotlin-android-extensions
Geob-o-matic
Geob-o-matic

Reputation: 6079

Kotlin synthetic and custom layout in DialogFragment

Let's say I have this layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<ImageButton
    android:id="@+id/add_dep_btn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignParentRight="true"
    android:layout_marginEnd="5dp"
    android:layout_marginRight="5dp"
    android:src="@android:drawable/ic_input_add" />

<EditText
    android:id="@+id/add_dep_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/add_dep_btn"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_alignTop="@id/add_dep_btn"
    android:layout_marginLeft="5dp"
    android:layout_marginStart="5dp"
    android:layout_toLeftOf="@id/add_dep_btn"
    android:layout_toStartOf="@id/add_dep_btn" />

<android.support.v7.widget.RecyclerView
    android:id="@+id/dep_list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/add_dep_btn" />

<TextView
    android:id="@+id/empty_text"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/add_dep_text"
    android:layout_margin="20dp"
    android:gravity="center"
    android:text="@string/no_dep"
    android:textSize="22sp" />
</RelativeLayout>

And I use it in a DialogFragment:

class DepartmentChoiceDialog : DialogFragment() {
    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val builder = AlertDialog.Builder(activity)
        builder.setTitle(R.string.choose_or_create_dep)
            .setView(R.layout.department_chooser_dialog)
            .setNegativeButton(android.R.string.cancel, { d, i ->
                d.cancel()
            })
        return builder.create()
    }
}

if I refer to the widget using synthetic:

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    dep_list.layoutManager = LinearLayoutManager(activity)
    dep_list.itemAnimator = DefaultItemAnimator()
    dep_list.setHasFixedSize(true)
}

I got this error at runtime:

java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference at MyDialog._$_findCachedViewById(DepartmentChoiceDialog.kt:0)

I don't understand how to use synthetic in DialogFragment case. It works fine in Fragment and Activity.

Upvotes: 30

Views: 18824

Answers (10)

ggaier
ggaier

Reputation: 381

Blockquote

The kotlin code in a Fragment like this:

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    return inflater.inflate(R.layout.your_layout, container, false).apply {
        mContentView = this
        button1.setOnClickListener { 
            //do something
        }
    }
}

After decompile the bytecode, you can see the implementation of synthetic properties:

((Button)this._$_findCachedViewById(id.button1))

and the _$_findCachedViewById method :

public View _$_findCachedViewById(int var1) {
  if (this._$_findViewCache == null) {
     this._$_findViewCache = new HashMap();
  }

  View var2 = (View)this._$_findViewCache.get(var1);
  if (var2 == null) {
     View var10000 = this.getView();
     if (var10000 == null) {
        return null;
     }

     var2 = var10000.findViewById(var1);
     this._$_findViewCache.put(var1, var2);
  }

  return var2;

}

so the magic is just the this.getView(). The Fragment.mView property is assigned after Fragment.onCreateView(inflater, container, savedInstanceState), if you use Kotlin Synthetic Properties in onCreateView() method, there will be a NPE. Code from FragmentManager.moveToState():

case Fragment.CREATED:
    ...
    f.mView = f.performCreateView(f.performGetLayoutInflater(
                                f.mSavedFragmentState), container, 
    f.mSavedFragmentState);
    ...

To fix the NPE, make sure getView method return a non-null view.

private var mContentView: View? = null
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    return inflater.inflate(R.layout.your_layout, container, false).apply {
        mContentView = this
    }
}
override fun getView(): View? {
    return mContentView
}

and at the onDestroyView() lifecycle callback, set mContentView to null.

override fun onDestroyView() {
    super.onDestroyView()
    mContentView = null
}

Upvotes: 1

XuesongZhang
XuesongZhang

Reputation: 11

The setContentView is inside the OnActivityCreated calls. So by a synthetic set of controls to monitor events needs to call here:

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

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
}

override fun onActivityCreated(savedInstanceState: Bundle?) {
    dialog?.window?.requestFeature(Window.FEATURE_NO_TITLE)
    super.onActivityCreated(savedInstanceState)
    dialog?.window?.setLayout(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT)

    btn_back?.setOnClickListener {
        mOnClickListener?.onClickCancel()
        dismiss()
    }
}

And it worked.

Upvotes: 1

Aceofspadez44
Aceofspadez44

Reputation: 234

So I'm not sure if this has been solved... I just came across this. If you have a custom Dialog view make a class that extends DialogFragment and use the "dialog" object to import views in the layout. I'm using Android Studio 3.1.3 and Kotlin version 1.2.41 at the time of writing.

import kotlinx.android.synthetic.main.your_custom_layout.*

class SelectCountryBottomSheet : BottomSheetDialogFragment() {

  override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
      val dialog = super.onCreateDialog(savedInstanceState) as BottomSheetDialog
      dialog.setContentView(R.layout.your_custom_layout)
      dialog.some_custom_close_button.setOnClickListener { dismiss() }
      return dialog
  }
}

Upvotes: 5

act262
act262

Reputation: 563

Because the default view's value from fragment(kotlin generate method _$_findCachedViewById), but if we create View from dialog, lead to fragment view is null, so we can't directly use default xxx , but we can use dialog.xxx replace default xxx

Upvotes: 2

Sabaat Ahmad
Sabaat Ahmad

Reputation: 540

I found a way that works for custom dialogs.

class ServerPickerDialogFragment: AppCompatDialogFragment() 
{
  // Save your custom view at the class level
  lateinit var customView: View;
  override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                            savedInstanceState: Bundle?): View? 
  {
       // Simply return the already inflated custom view
       return customView
  }

  override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
      // Inflate your view here
      customView = context!!.layoutInflater.inflate(R.layout.dialog_server_picker, null) 
      // Create Alert Dialog with your custom view
      return AlertDialog.Builder(context!!)
             .setTitle(R.string.server_picker_dialog_title)
             .setView(customView)
             .setNegativeButton(android.R.string.cancel, null)
             .create()
  }

  override fun onViewCreated(view: View, savedInstanceState: Bundle?) 
  {
    super.onViewCreated(view, savedInstanceState)
    // Perform remaining operations here. No null issues.
    rbgSelectType.setOnCheckedChangeListener({ _, checkedId ->
      if(checkedId == R.id.rbSelectFromList) {
             // XYZ
      } else {
             // ABC
      }
    })
  }
}

Upvotes: 14

SUPERCILEX
SUPERCILEX

Reputation: 4007

It looks like this isn't supported by default yet, but I've found the easiest way to do it to be like this. In a base dialog class:

protected abstract val containerView: View

override fun getView() = containerView

In a subclass:

override val containerView by unsafeLazy {
    View.inflate(context, R.layout.dialog_team_details, null) as ViewGroup
}

Then you can use the synthetic views as you normally would and use the containerView as the view for your dialog.

Upvotes: 10

Lucas Montano
Lucas Montano

Reputation: 109

Change to onCreateView implementation

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

and use a custom title(TextView) and cancel(Button) in the department_chooser_dialog

onActivityCreated will run after onCreateView and will be just fine.

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    dep_list.layoutManager = LinearLayoutManager(activity)
    dep_list.itemAnimator = DefaultItemAnimator()
    dep_list.setHasFixedSize(true)
}

Upvotes: 4

Willi Mentzel
Willi Mentzel

Reputation: 29844

The views are accessible via the view that you inflate in onCreateDialog. So, if you save the view in a variable (rootView) you can access the views from any method inside of YourDialogFragment.

// ...
import kotlinx.android.synthetic.main.your_layout.view.*

class YourDialogFragment : DialogFragment() {

    private lateinit var rootView: View

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {

        rootView = activity.layoutInflater.inflate(R.layout.your_layout, null as ViewGroup?)

        rootView.someTextView.text = "Hello" // works
    }
}

Upvotes: -1

Andriy Koretskyy
Andriy Koretskyy

Reputation: 575

Previous answer will not work, because onViewCreated is not called when you use onCreateDialog. You should first import kotlinx...department_chooser_dialog.view.dep_list, an then use it as follows:

import kotlinx.android.synthetic.main.department_chooser_dialog.view.dep_list
...
class DepartmentChoiceDialog : DialogFragment() {
    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val builder = AlertDialog.Builder(activity)
        val dialog = inflater.inflate(R.layout.department_chooser_dialog, null)
        dialog.dep_list.layoutManager = LinearLayoutManager(activity)
        dialog.dep_list.itemAnimator = DefaultItemAnimator()
        dialog.dep_list.setHasFixedSize(true)
        builder.setTitle(R.string.choose_or_create_dep)
               .setView(dialog)
                    ...

Upvotes: 6

Ferenc Boldog
Ferenc Boldog

Reputation: 62

Move your code from onActivityCreated to onViewCreated method. Like this:

import kotlinx.android.synthetic.main.department_chooser_dialog.dep_list

override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    dep_list.apply {
        layoutManager = LinearLayoutManager(activity)
        itemAnimator = DefaultItemAnimator()
        setHasFixedSize(true)
    }
}

I actually didn't look deeper into generated code and maybe there is a bug.

Upvotes: 0

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