Add custom ListPreference

app/src/main/java/com/hippo/preference/ListPreference.java

@@ -0,0 +1,349 @@
+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * 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.hippo.preference;
+
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.res.TypedArray;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.support.annotation.ArrayRes;
+import android.support.v7.app.AlertDialog;
+import android.text.TextUtils;
+import android.util.AttributeSet;
+
+import com.hippo.ehviewer.R;
+
+public class ListPreference extends DialogPreference {
+
+    private CharSequence[] mEntries;
+    private CharSequence[] mEntryValues;
+    private String mValue;
+    private String mSummary;
+    private int mClickedDialogEntryIndex;
+    private boolean mValueSet;
+
+    public ListPreference(Context context) {
+        super(context);
+        init(context, null, 0, 0);
+    }
+
+    public ListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(context, attrs, 0, 0);
+    }
+
+    public ListPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(context, attrs, defStyleAttr, 0);
+    }
+
+    public ListPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    private void init(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        setNegativeButtonText(android.R.string.cancel);
+
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ListPreference, defStyleAttr, defStyleRes);
+        mEntries = a.getTextArray(R.styleable.ListPreference_entries);
+        mEntryValues = a.getTextArray(R.styleable.ListPreference_entryValues);
+        a.recycle();
+
+        /* Retrieve the Preference summary attribute since it's private
+         * in the Preference class.
+         */
+        a = context.obtainStyledAttributes(attrs, new int[]{android.R.attr.summary}, defStyleAttr, defStyleRes);
+        mSummary = a.getString(0);
+        a.recycle();
+    }
+
+    /**
+     * Sets the human-readable entries to be shown in the list. This will be
+     * shown in subsequent dialogs.
+     * <p>
+     * Each entry must have a corresponding index in
+     * {@link #setEntryValues(CharSequence[])}.
+     *
+     * @param entries The entries.
+     * @see #setEntryValues(CharSequence[])
+     */
+    public void setEntries(CharSequence[] entries) {
+        mEntries = entries;
+    }
+
+    /**
+     * @see #setEntries(CharSequence[])
+     * @param entriesResId The entries array as a resource.
+     */
+    public void setEntries(@ArrayRes int entriesResId) {
+        setEntries(getContext().getResources().getTextArray(entriesResId));
+    }
+
+    /**
+     * The list of entries to be shown in the list in subsequent dialogs.
+     *
+     * @return The list as an array.
+     */
+    public CharSequence[] getEntries() {
+        return mEntries;
+    }
+
+    /**
+     * The array to find the value to save for a preference when an entry from
+     * entries is selected. If a user clicks on the second item in entries, the
+     * second item in this array will be saved to the preference.
+     *
+     * @param entryValues The array to be used as values to save for the preference.
+     */
+    public void setEntryValues(CharSequence[] entryValues) {
+        mEntryValues = entryValues;
+    }
+
+    /**
+     * @see #setEntryValues(CharSequence[])
+     * @param entryValuesResId The entry values array as a resource.
+     */
+    public void setEntryValues(@ArrayRes int entryValuesResId) {
+        setEntryValues(getContext().getResources().getTextArray(entryValuesResId));
+    }
+
+    /**
+     * Returns the array of values to be saved for the preference.
+     *
+     * @return The array of values.
+     */
+    public CharSequence[] getEntryValues() {
+        return mEntryValues;
+    }
+
+    /**
+     * Sets the value of the key. This should be one of the entries in
+     * {@link #getEntryValues()}.
+     *
+     * @param value The value to set for the key.
+     */
+    public void setValue(String value) {
+        // Always persist/notify the first time.
+        final boolean changed = !TextUtils.equals(mValue, value);
+        if (changed || !mValueSet) {
+            mValue = value;
+            mValueSet = true;
+            persistString(value);
+            if (changed) {
+                notifyChanged();
+            }
+        }
+    }
+
+    /**
+     * Returns the summary of this ListPreference. If the summary
+     * has a {@linkplain java.lang.String#format String formatting}
+     * marker in it (i.e. "%s" or "%1$s"), then the current entry
+     * value will be substituted in its place.
+     *
+     * @return the summary with appropriate string substitution
+     */
+    @Override
+    public CharSequence getSummary() {
+        final CharSequence entry = getEntry();
+        if (mSummary == null) {
+            return super.getSummary();
+        } else {
+            return String.format(mSummary, entry == null ? "" : entry);
+        }
+    }
+
+    /**
+     * Sets the summary for this Preference with a CharSequence.
+     * If the summary has a
+     * {@linkplain java.lang.String#format String formatting}
+     * marker in it (i.e. "%s" or "%1$s"), then the current entry
+     * value will be substituted in its place when it's retrieved.
+     *
+     * @param summary The summary for the preference.
+     */
+    @Override
+    public void setSummary(CharSequence summary) {
+        super.setSummary(summary);
+        if (summary == null && mSummary != null) {
+            mSummary = null;
+        } else if (summary != null && !summary.equals(mSummary)) {
+            mSummary = summary.toString();
+        }
+    }
+
+    /**
+     * Sets the value to the given index from the entry values.
+     *
+     * @param index The index of the value to set.
+     */
+    public void setValueIndex(int index) {
+        if (mEntryValues != null) {
+            setValue(mEntryValues[index].toString());
+        }
+    }
+
+    /**
+     * Returns the value of the key. This should be one of the entries in
+     * {@link #getEntryValues()}.
+     *
+     * @return The value of the key.
+     */
+    public String getValue() {
+        return mValue;
+    }
+
+    /**
+     * Returns the entry corresponding to the current value.
+     *
+     * @return The entry corresponding to the current value, or null.
+     */
+    public CharSequence getEntry() {
+        int index = getValueIndex();
+        return index >= 0 && mEntries != null ? mEntries[index] : null;
+    }
+
+    /**
+     * Returns the index of the given value (in the entry values array).
+     *
+     * @param value The value whose index should be returned.
+     * @return The index of the value, or -1 if not found.
+     */
+    public int findIndexOfValue(String value) {
+        if (value != null && mEntryValues != null) {
+            for (int i = mEntryValues.length - 1; i >= 0; i--) {
+                if (mEntryValues[i].equals(value)) {
+                    return i;
+                }
+            }
+        }
+        return -1;
+    }
+
+    private int getValueIndex() {
+        return findIndexOfValue(mValue);
+    }
+
+    @Override
+    protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
+        super.onPrepareDialogBuilder(builder);
+
+        if (mEntries == null || mEntryValues == null) {
+            throw new IllegalStateException(
+                    "ListPreference requires an entries array and an entryValues array.");
+        }
+
+        mClickedDialogEntryIndex = getValueIndex();
+        builder.setSingleChoiceItems(mEntries, mClickedDialogEntryIndex,
+                new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        mClickedDialogEntryIndex = which;
+
+                        /*
+                         * Clicking on an item simulates the positive button
+                         * click, and dismisses the dialog.
+                         */
+                        ListPreference.this.onClick(dialog, DialogInterface.BUTTON_POSITIVE);
+                        dialog.dismiss();
+                    }
+                });
+    }
+
+    @Override
+    protected void onDialogClosed(boolean positiveResult) {
+        super.onDialogClosed(positiveResult);
+
+        if (positiveResult && mClickedDialogEntryIndex >= 0 && mEntryValues != null) {
+            String value = mEntryValues[mClickedDialogEntryIndex].toString();
+            if (callChangeListener(value)) {
+                setValue(value);
+            }
+        }
+    }
+
+    @Override
+    protected Object onGetDefaultValue(TypedArray a, int index) {
+        return a.getString(index);
+    }
+
+    @Override
+    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
+        setValue(restoreValue ? getPersistedString(mValue) : (String) defaultValue);
+    }
+
+    @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.value = getValue();
+        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());
+        setValue(myState.value);
+    }
+
+    private static class SavedState extends BaseSavedState {
+        String value;
+
+        public SavedState(Parcel source) {
+            super(source);
+            value = source.readString();
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            super.writeToParcel(dest, flags);
+            dest.writeString(value);
+        }
+
+        public SavedState(Parcelable superState) {
+            super(superState);
+        }
+
+        public static final Parcelable.Creator<SavedState> CREATOR =
+                new Parcelable.Creator<SavedState>() {
+                    @Override
+                    public SavedState createFromParcel(Parcel in) {
+                        return new SavedState(in);
+                    }
+
+                    @Override
+                    public SavedState[] newArray(int size) {
+                        return new SavedState[size];
+                    }
+                };
+    }
+
+}