我正在使用Mortar + Flow构建我的应用程序。我试图找出正确的方法来显示一个向用户请求一些文本的弹出窗口。我创建了这个弹出类:
public class SavedPageTitleInputPopup implements Popup<SavedPageTitleInput, Optional<String>> {
private final Context context;
private AlertDialog dialog;
public SavedPageTitleInputPopup(Context context) {
this.context = context;
}
@Override public Context getContext() {
return context;
}
@Override
public void show(final SavedPageTitleInput info, boolean withFlourish,
final PopupPresenter<SavedPageTitleInput, Optional<String>> presenter) {
if (dialog != null) throw new IllegalStateException("Already showing, can't show " + info);
final EditText input = new EditText(context);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
input.setLayoutParams(lp);
input.setText(info.savedPage.getName());
dialog = new AlertDialog.Builder(context).setTitle(info.title)
.setView(input)
.setMessage(info.body)
.setPositiveButton(info.confirm, new DialogInterface.OnClickListener() {
@Override public void onClick(DialogInterface d, int which) {
dialog = null;
final String newTitle = Strings.emptyToNull(String.valueOf(input.getText()));
presenter.onDismissed(Optional.fromNullable(newTitle));
}
})
.setNegativeButton(info.cancel, new DialogInterface.OnClickListener() {
@Override public void onClick(DialogInterface d, int which) {
dialog = null;
presenter.onDismissed(Optional.<String>absent());
}
})
.setCancelable(true)
.setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override public void onCancel(DialogInterface d) {
dialog = null;
presenter.onDismissed(Optional.<String>absent());
}
})
.show();
}
@Override public boolean isShowing() {
return dialog != null;
}
@Override public void dismiss(boolean withFlourish) {
dialog.dismiss();
dialog = null;
}
}
此类按预期工作。它使用SavedPage
来确定要在对话框中显示的内容,并在按下正确的按钮时将用户输入返回给PopupPresenter
using PopupPresenter#onDismissed 。
我的问题是编写PopupPresenter
用于呈现对话框和处理输入的子类。这就是我现在所拥有的:
new PopupPresenter<SavedPage, Optional<String>>() {
@Override protected void onPopupResult(Optional<String> result) {
if (result.isPresent()) {
// The user entered something, so update the API
// Oh wait, I don't have a reference to the SavedPage
// that was displayed in the dialog!
}
}
}
正如评论所说,我没有引用SavedPage
对话框中显示的内容。它存储在 中的whatToShow
字段中PopupPresenter
,但在调用之前该字段被清空onPopupResult
。似乎我会不必要地重复自己以保留SavedPage
.