src/com/android/emergency/preferences/AutoCompleteEditTextPreference.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.emergency.preferences;

import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.res.TypedArray;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v14.preference.PreferenceDialogFragment;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.Window;
import android.view.WindowManager;
import android.view.inputmethod.EditorInfo;
import android.widget.AutoCompleteTextView;
import android.widget.TextView;

import com.android.emergency.R;
import com.android.internal.annotations.VisibleForTesting;
import com.android.settingslib.CustomDialogPreference;

/**
 * Almost a copy of EditTextPreference that shows a {@link AutoCompleteTextView} instead of the
 * basic EditText. It always show the suggested options.
 * TODO: an EditTextPreference always shows the soft input keyboard, whereas this class does not,
 * and it should, to mimic EditTextPreference better.
 */
public class AutoCompleteEditTextPreference extends CustomDialogPreference {
    /**
     * The edit text shown in the dialog.
     */
    private AutoCompleteTextView mAutoCompleteTextView;

    private String mText;
    private boolean mTextSet;

    public AutoCompleteEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr,
            int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);

        mAutoCompleteTextView = new InstantAutoCompleteTextView(context, attrs);

        // Give it an ID so it can be saved/restored
        mAutoCompleteTextView.setId(R.id.edit);

        /*
         * The preference framework and view framework both have an 'enabled'
         * attribute. Most likely, the 'enabled' specified in this XML is for
         * the preference framework, but it was also given to the view framework.
         * We reset the enabled state.
         */
        mAutoCompleteTextView.setEnabled(true);

        mAutoCompleteTextView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_DONE) {
                    onClick(getDialog(), DialogInterface.BUTTON_POSITIVE);
                    getDialog().dismiss();
                    return true;
                }
                return false;
            }
        });
        setDialogLayoutResource(R.layout.preference_dialog_autocomplete_edittext);
    }

    public AutoCompleteEditTextPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public AutoCompleteEditTextPreference(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.dialogPreferenceStyle);
    }

    public AutoCompleteEditTextPreference(Context context) {
        this(context, null);
    }

    public AutoCompleteTextView getAutoCompleteTextView() {
        return mAutoCompleteTextView;
    }

    /**
     * Saves the text to the {@link SharedPreferences}.
     *
     * @param text The text to save
     */
    public void setText(String text) {
        // Always persist/notify the first time.
        final boolean changed = !TextUtils.equals(mText, text);
        if (changed || !mTextSet) {
            mText = text;
            mTextSet = true;
            persistString(text);
            if (changed) {
                notifyDependencyChange(shouldDisableDependents());
                notifyChanged();
            }
        }
    }

    @VisibleForTesting
    @Override
    public void onClick() {
        super.onClick();
    }

    /**
     * Gets the text from the {@link SharedPreferences}.
     *
     * @return The current preference value.
     */
    public String getText() {
        return mText;
    }

    @Override
    protected void onBindDialogView(View view) {
        super.onBindDialogView(view);

        AutoCompleteTextView editText = mAutoCompleteTextView;
        editText.setText(getText());
        editText.requestFocus();

        ViewParent oldParent = editText.getParent();
        if (oldParent != view) {
            if (oldParent != null) {
                ((ViewGroup) oldParent).removeView(editText);
            }
            onAddEditTextToDialogView(view, editText);
        }
        editText.setSelection(editText.getText().length());
    }

    /**
     * Adds the AutoCompleteTextView widget of this preference to the dialog's view.
     *
     * @param dialogView The dialog view.
     */
    protected void onAddEditTextToDialogView(View dialogView, AutoCompleteTextView editText) {
        ViewGroup container = (ViewGroup) dialogView
                .findViewById(R.id.autocomplete_edittext_container);
        if (container != null) {
            container.addView(editText, ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
        }
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
        super.onDialogClosed(positiveResult);

        if (positiveResult) {
            String value = mAutoCompleteTextView.getText().toString();
            if (callChangeListener(value)) {
                setText(value);
            }
        }
    }

    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        return a.getString(index);
    }

    @Override
    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
        setText(restoreValue ? getPersistedString(mText) : (String) defaultValue);
    }

    @Override
    public boolean shouldDisableDependents() {
        return TextUtils.isEmpty(mText) || super.shouldDisableDependents();
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        final Parcelable superState = super.onSaveInstanceState();
        if (isPersistent()) {
            // No need to save instance state since it's persistent
            return superState;
        }

        final SavedState myState = new SavedState(superState);
        myState.text = getText();
        return myState;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (state == null || !state.getClass().equals(SavedState.class)) {
            // Didn't save state for us in onSaveInstanceState
            super.onRestoreInstanceState(state);
            return;
        }

        SavedState myState = (SavedState) state;
        super.onRestoreInstanceState(myState.getSuperState());
        setText(myState.text);
    }

    private static class SavedState extends BaseSavedState {
        String text;

        public SavedState(Parcel source) {
            super(source);
            text = source.readString();
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            super.writeToParcel(dest, flags);
            dest.writeString(text);
        }

        public SavedState(Parcelable superState) {
            super(superState);
        }

        public static final Parcelable.Creator<SavedState> CREATOR =
                new Parcelable.Creator<SavedState>() {
                    public SavedState createFromParcel(Parcel in) {
                        return new SavedState(in);
                    }

                    public SavedState[] newArray(int size) {
                        return new SavedState[size];
                    }
                };
    }

    /** {@link AutoCompleteTextView} that always shows the suggestions. */
    private class InstantAutoCompleteTextView extends AutoCompleteTextView {
        public InstantAutoCompleteTextView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        @Override
        public boolean enoughToFilter() {
            return true;
        }

        @Override
        protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
            super.onFocusChanged(focused, direction, previouslyFocusedRect);

            showDropDownIfFocused();
        }

        @Override
        protected void onAttachedToWindow() {
            super.onAttachedToWindow();
            showDropDownIfFocused();
        }

        private void showDropDownIfFocused() {
            if (isFocused() && getWindowVisibility() == View.VISIBLE) {
                showDropDown();
            }
        }
    }

    public static class AutoCompleteEditTextPreferenceDialogFragment
            extends CustomDialogPreference.CustomPreferenceDialogFragment {
        public static CustomDialogPreference.CustomPreferenceDialogFragment
                newInstance(String key) {
            return CustomDialogPreference.CustomPreferenceDialogFragment.newInstance(key);
        }
    }
}