【发布时间】：2015-08-25 09:19:12
【问题描述】：
我正在使用 PreferenceActivity 来设置我的应用。 我想添加一个允许用户选择图标的新首选项。 对于这个任务，我想使用 ListPreference，但我还想在列表中显示图标。
我尝试自定义 ListPreference 以使用自定义布局，但问题是一旦我这样做，列表项就不可点击（它确实显示了我的自定义布局并使用默认值当前选择）。
我在不同的模拟器版本和 Galaxy S2 上对其进行了测试。按下项目时，我可以看到按下/未按下的一些效果，但没有调用 onClick 方法。
我按照Android: Checkable Linear Layout 上的说明添加自定义布局（我也尝试了How to customize list preference radio button 中描述的选项，但结果相同）。
IconTypePreference.java（从ListPreference复制并修改）：
public class IconTypePreference extends DialogPreference {
private IconType value;
private int clickedDialogIndex;
private boolean valueSet;
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public IconTypePreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
public IconTypePreference(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public IconTypePreference(Context context, AttributeSet attrs) {
super(context, attrs);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public IconTypePreference(Context context) {
super(context);
}
public void setValue(String value) {
// Always persist/notify the first time.
final boolean changed = !TextUtils.equals(getValueText(), value);
if (changed || !valueSet) {
if (value == null) {
this.value = null;
} else {
this.value = IconType.valueOf(value);
}
valueSet = true;
persistString(value);
if (changed) {
notifyChanged();
}
}
}
public void setValueIndex(int index) {
setValue(IconType.values()[index].toString());
}
public IconType getValue() {
return value;
}
public String getValueText() {
return (value == null ? null : value.toString());
}
public int findIndexOfValue(String value) {
IconType[] values = IconType.values();
for (int i = values.length - 1; i >= 0; i--) {
if (values[i].toString().equals(value)) {
return i;
}
}
return -1;
}
private int getValueIndex() {
return findIndexOfValue(getValueText());
}
@Override
protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
super.onPrepareDialogBuilder(builder);
clickedDialogIndex = getValueIndex();
builder.setSingleChoiceItems(new IconTypeAdapter(getContext()), clickedDialogIndex,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
clickedDialogIndex = which;
IconTypePreference.this.onClick(dialog, DialogInterface.BUTTON_POSITIVE);
dialog.dismiss();
}
});
/*
* The typical interaction for list-based dialogs is to have
* click-on-an-item dismiss the dialog instead of the user having to
* press 'Ok'.
*/
builder.setPositiveButton(null, null);
}
@Override
protected void onDialogClosed(boolean positiveResult) {
super.onDialogClosed(positiveResult);
if (positiveResult && clickedDialogIndex >= 0) {
String value = IconType.values()[clickedDialogIndex].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(getValueText()) : (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 = getValueText();
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>() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
private static class IconTypeAdapter extends ArrayAdapter<IconType> {
private final String[] iconTypeText;
private LayoutInflater inflater;
public IconTypeAdapter(Context context) {
super(context, R.layout.icon_type_item, IconType.values());
this.inflater = LayoutInflater.from(context);
iconTypeText = context.getResources().getStringArray(R.array.icon_type);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.icon_type_item, parent, false);
}
((TextView)convertView.findViewById(R.id.text)).setText(iconTypeText[position]);
convertView.setClickable(true);
// todo: set view text
return convertView;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public long getItemId(int position) {
return position;
}
}
}
CheckableLinearLayout.java
public class CheckableLinearLayout extends LinearLayout implements Checkable {
private Checkable checkable;
public CheckableLinearLayout(Context context) {
super(context);
}
public CheckableLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public CheckableLinearLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public CheckableLinearLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
// setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
checkable = getCheckable(this);
if (checkable == null) {
throw new RuntimeException("Missing Checkable component");
}
}
private Checkable getCheckable(ViewGroup viewGroup) {
View v;
int childCount = viewGroup.getChildCount();
for (int i = 0; i < childCount; ++i) {
v = getChildAt(i);
if (v instanceof Checkable) {
return (Checkable)v;
} else if (v instanceof ViewGroup) {
Checkable result = getCheckable((ViewGroup)v);
if (result != null) {
return result;
}
}
}
return null;
}
@Override
public void setChecked(boolean checked) {
checkable.setChecked(checked);
}
@Override
public boolean isChecked() {
return checkable.isChecked();
}
@Override
public void toggle() {
checkable.toggle();
}
}
icon_type_item.xml
<?xml version="1.0" encoding="utf-8"?>
<com.utils.ui.widget.CheckableLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView android:id="@+id/text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:focusable="false"
android:focusableInTouchMode="false"/>
<RadioButton android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="false"
android:focusable="false"
android:focusableInTouchMode="false"/>
</com.utils.ui.widget.CheckableLinearLayout>
添加到 settings.xml
<com.utils.ui.preference.IconTypePreference
android:key="icon_type"
android:defaultValue="type_b"
android:title="@string/icon_type_preference_title"/>
编辑
CheckableLinearLayout.java
中有一个错误将 getCheckable 方法替换为：
private Checkable getCheckable(ViewGroup viewGroup) {
View v;
int childCount = viewGroup.getChildCount();
for (int i = 0; i < childCount; ++i) {
v = viewGroup.getChildAt(i);
if (v instanceof Checkable) {
return (Checkable)v;
} else if (v instanceof ViewGroup) {
Checkable result = getCheckable((ViewGroup)v);
if (result != null) {
return result;
}
}
}
return null;
}
【问题讨论】：
标签： android android-preferences