协调跨子 Fragments/Activities 的浮动操作按钮行为
Coordinating Floating-Action Button behaviour across Child Fragments/Activities
我在协调 Activity 中的浮动操作按钮及其子项的行为时遇到问题。
在我的应用程序中,我有一个 Activity
,其中包含一个 ViewPager
和一个由 following library 构建的 xml
定义的 FloatingActionMenu
。 ViewPager
包含灵活数量的 Fragments
,每个 Fragment
内有一个 RecyclerView
。
单击时,FloatingActionMenu
会扩展为两个按钮 - 一个向 ViewPager
添加一个额外的 page/Fragment,另一个向 RecyclerView
添加一个额外的行用户当前所在的 ViewPager
的页面。此功能有效。
为了隐藏按钮,我在我的子片段中使用 addOnItemTouchListener
到 RecyclerView
。然后,在 OnInterceptTouchEvent
中,如果滑动手势足够大,我使用自定义 Interface
将事件中继回宿主 Activity
,后者执行动画以隐藏或显示按钮.这是我的一些代码:
public class Categories extends ActionBarActivity implements
View.OnClickListener,
FloatingButtonInterface{
//...
// Final parameter is for the custom Interface
mAdapter = new CategoriesViewPagerAdapter(mFragmentManager, allCategoriesCursor, this);
mViewPager = (ViewPager) findViewById(R.id.categories_view_pager_pager);
mViewPager.setAdapter(mAdapter);
menuOriginalXPos = mFloatingActionsMenu.getX();
menuOriginalYPos = mFloatingActionsMenu.getY();
//...
// onTouchEvent is the imaginative name for my custom Interface method.
@Override
public void onTouchEvent(int callBackID) {
if (callBackID == FloatingButtonInterface.MOTION_DOWN){
if (mFloatingActionsMenu.getVisibility() == View.GONE) {
Animation translate = new TranslateAnimation(
menuOriginalXPos, menuOriginalXPos, mViewPager.getHeight(), menuOriginalYPos);
translate.setDuration(250);
translate.setInterpolator(new LinearInterpolator());
mFloatingActionsMenu.startAnimation(translate);
mFloatingActionsMenu.setEnabled(true);
mFloatingActionsMenu.setVisibility(View.VISIBLE);
}
} else if (callBackID == FloatingButtonInterface.MOTION_UP) {
if (mFloatingActionsMenu.getVisibility() == View.VISIBLE) {
Animation translate = new TranslateAnimation(
menuOriginalXPos, menuOriginalXPos, menuOriginalYPos, mViewPager.getHeight());
translate.setDuration(250);
translate.setInterpolator(new LinearInterpolator());
mFloatingActionsMenu.startAnimation(translate);
mFloatingActionsMenu.setEnabled(false);
mFloatingActionsMenu.setVisibility(View.GONE);
}
}
}
这是我非常直接的界面:
public interface FloatingButtonInterface {
public static final int MOTION_UP = 4;
public static final int MOTION_DOWN = MOTION_UP+1;
public static final int MOTION_NONE = 0;
public void onTouchEvent(int callBackID);
}
在我的 ViewPager
里面:
public class CategoriesViewPagerAdapter extends FragmentStatePagerAdapter {
private static final String LOG_TAG = "CategoriesViewPagerAd";
private Cursor mCursor;
private FloatingButtonInterface hideMenuInterface;
private FragmentManager mFragmentManager;
private boolean refreshItem = false;
public CategoriesViewPagerAdapter(FragmentManager fm, Cursor data, FloatingButtonInterface hideMenuInterface) {
super(fm);
mCursor = data;
mFragmentManager = fm;
this.hideMenuInterface = hideMenuInterface;
}
@Override
public Fragment getItem(int i) {
mCursor.moveToPosition(i);
int categoryFragmentIdentifier =
mCursor.getInt(mCursor.getColumnIndex(FilesDatabaseHelper.KEY_ID));
CategoryFragment frag = CategoryFragment.newInstance(categoryFragmentIdentifier);
frag.setOnTouchEvent(hideMenuInterface);
return frag;
}
最后,ViewPager
Fragment
之一:
public class CategoryFragment extends Fragment implements
RecyclerView.OnItemTouchListener,
View.OnClickListener{
//...
private static final int TOUCH_SLOP=200;
//...
static CategoryFragment newInstance(int categoryIdentifier){
CategoryFragment frag = new CategoryFragment();
Bundle bundle = new Bundle();
bundle.putInt(CATEGORY_ID, categoryIdentifier);
frag.setArguments(bundle);
return frag;
}
//...
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mRecyclerView.addOnItemTouchListener(this);
//...
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
switch (e.getAction()){
case MotionEvent.ACTION_DOWN:
originalFingerPos = e.getY();
break;
case MotionEvent.ACTION_MOVE:
if (e.getY() - originalFingerPos > TOUCH_SLOP){
if (hideMenuInterface != null) {
hideMenuInterface.onTouchEvent(FloatingButtonInterface.MOTION_DOWN);
} else {
Log.e(LOG_TAG, "hideMenuInterface is null");
}
} else if (e.getY() + TOUCH_SLOP < originalFingerPos ){
if (hideMenuInterface != null) {
hideMenuInterface.onTouchEvent(FloatingButtonInterface.MOTION_UP);
} else {
Log.e(LOG_TAG, "hideMenuInterface is null");
}
}
}
return false;
}
我遇到的主要问题与用户在更改配置后在屏幕上向上或向下滑动时用于自动隐藏按钮的代码有关。如果我在测试设备上更改屏幕方向,当我尝试通过滑动隐藏按钮时,一些 Fragments
没有响应,当我检查 LogCat
时,我可以看到 hideMenuInterface
是 null
。我能做些什么来解决这个问题?为什么它只影响一些片段而不是所有片段?如果我滑动到 ViewPager 中的最后一个片段然后再次返回,问题就会自行解决 - 可能是因为片段已被重新创建。
感谢您提供的任何见解!我只包含了我认为相关的代码,否则会有页面,但请询问您是否认为还有其他帮助。
我在 Android Developer docs 中找到了这个问题的答案。按照此页面上的说明操作后,按钮行为更加可靠。
编辑:
为了扩展我之前的回答,我通过以下方式应用了文档中的信息:
我通过添加一个名为 FloatingButtonInterface
的内部 interface
来更改 CategoryFragment
(占据每个 ViewPager
项目的片段),并为 [=15] 赋值=] onAttach()
期间的变量:
public class CategoryFragment extends Fragment implements RecyclerView.OnItemTouchListener {
//...
private static final int TOUCH_SLOP = 200;
private FloatingButtonInterface floatingButtonInterface;
//...
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
floatingButtonInterface = (FloatingButtonInterface) activity;
}
//...
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
originalFingerPos = e.getY();
return false;
case MotionEvent.ACTION_MOVE:
if (e.getY() - originalFingerPos > TOUCH_SLOP) {
floatingButtonInterface.onTouchEvent(FloatingButtonInterface.MOTION_DOWN);
return false;
} else if (e.getY() + TOUCH_SLOP < originalFingerPos) {
floatingButtonInterace.onTouchEvent(FloatingButtonInterface.MOTION_UP);
return false;
}
return false;
}
return false;
}
//...
public interface FloatingButtonInterface {
public static final int MOTION_UP = MOTION_NONE + 4;
public static final int MOTION_DOWN = MOTION_UP + 1;
public static final int MOTION_NONE = 0;
public void onTouchEvent(int callBackId);
}
唯一的其他变化是在 ViewPagerAdapter
内部。由于 CategoryFragment
负责分配接口,适配器中与此相关的任何代码都可以删除,因此适配器现在看起来像:
public class CategoriesViewPagerAdapter extends FragmentStatePagerAdapter {
private static final String LOG_TAG = "CategoriesViewPagerAd";
private Cursor mCursor;
private FloatingButtonInterface hideMenuInterface;
private FragmentManager mFragmentManager;
private boolean refreshItem = false;
public CategoriesViewPagerAdapter(FragmentManager fm, Cursor data) {
super(fm);
mCursor = data;
mFragmentManager = fm;
}
@Override
public Fragment getItem(int i) {
mCursor.moveToPosition(i);
int categoryFragmentIdentifier =
mCursor.getInt(mCursor.getColumnIndex(FilesDatabaseHelper.KEY_ID));
CategoryFragment frag = CategoryFragment.newInstance(categoryFragmentIdentifier);
return frag;
}
我在协调 Activity 中的浮动操作按钮及其子项的行为时遇到问题。
在我的应用程序中,我有一个 Activity
,其中包含一个 ViewPager
和一个由 following library 构建的 xml
定义的 FloatingActionMenu
。 ViewPager
包含灵活数量的 Fragments
,每个 Fragment
内有一个 RecyclerView
。
单击时,FloatingActionMenu
会扩展为两个按钮 - 一个向 ViewPager
添加一个额外的 page/Fragment,另一个向 RecyclerView
添加一个额外的行用户当前所在的 ViewPager
的页面。此功能有效。
为了隐藏按钮,我在我的子片段中使用 addOnItemTouchListener
到 RecyclerView
。然后,在 OnInterceptTouchEvent
中,如果滑动手势足够大,我使用自定义 Interface
将事件中继回宿主 Activity
,后者执行动画以隐藏或显示按钮.这是我的一些代码:
public class Categories extends ActionBarActivity implements
View.OnClickListener,
FloatingButtonInterface{
//...
// Final parameter is for the custom Interface
mAdapter = new CategoriesViewPagerAdapter(mFragmentManager, allCategoriesCursor, this);
mViewPager = (ViewPager) findViewById(R.id.categories_view_pager_pager);
mViewPager.setAdapter(mAdapter);
menuOriginalXPos = mFloatingActionsMenu.getX();
menuOriginalYPos = mFloatingActionsMenu.getY();
//...
// onTouchEvent is the imaginative name for my custom Interface method.
@Override
public void onTouchEvent(int callBackID) {
if (callBackID == FloatingButtonInterface.MOTION_DOWN){
if (mFloatingActionsMenu.getVisibility() == View.GONE) {
Animation translate = new TranslateAnimation(
menuOriginalXPos, menuOriginalXPos, mViewPager.getHeight(), menuOriginalYPos);
translate.setDuration(250);
translate.setInterpolator(new LinearInterpolator());
mFloatingActionsMenu.startAnimation(translate);
mFloatingActionsMenu.setEnabled(true);
mFloatingActionsMenu.setVisibility(View.VISIBLE);
}
} else if (callBackID == FloatingButtonInterface.MOTION_UP) {
if (mFloatingActionsMenu.getVisibility() == View.VISIBLE) {
Animation translate = new TranslateAnimation(
menuOriginalXPos, menuOriginalXPos, menuOriginalYPos, mViewPager.getHeight());
translate.setDuration(250);
translate.setInterpolator(new LinearInterpolator());
mFloatingActionsMenu.startAnimation(translate);
mFloatingActionsMenu.setEnabled(false);
mFloatingActionsMenu.setVisibility(View.GONE);
}
}
}
这是我非常直接的界面:
public interface FloatingButtonInterface {
public static final int MOTION_UP = 4;
public static final int MOTION_DOWN = MOTION_UP+1;
public static final int MOTION_NONE = 0;
public void onTouchEvent(int callBackID);
}
在我的 ViewPager
里面:
public class CategoriesViewPagerAdapter extends FragmentStatePagerAdapter {
private static final String LOG_TAG = "CategoriesViewPagerAd";
private Cursor mCursor;
private FloatingButtonInterface hideMenuInterface;
private FragmentManager mFragmentManager;
private boolean refreshItem = false;
public CategoriesViewPagerAdapter(FragmentManager fm, Cursor data, FloatingButtonInterface hideMenuInterface) {
super(fm);
mCursor = data;
mFragmentManager = fm;
this.hideMenuInterface = hideMenuInterface;
}
@Override
public Fragment getItem(int i) {
mCursor.moveToPosition(i);
int categoryFragmentIdentifier =
mCursor.getInt(mCursor.getColumnIndex(FilesDatabaseHelper.KEY_ID));
CategoryFragment frag = CategoryFragment.newInstance(categoryFragmentIdentifier);
frag.setOnTouchEvent(hideMenuInterface);
return frag;
}
最后,ViewPager
Fragment
之一:
public class CategoryFragment extends Fragment implements
RecyclerView.OnItemTouchListener,
View.OnClickListener{
//...
private static final int TOUCH_SLOP=200;
//...
static CategoryFragment newInstance(int categoryIdentifier){
CategoryFragment frag = new CategoryFragment();
Bundle bundle = new Bundle();
bundle.putInt(CATEGORY_ID, categoryIdentifier);
frag.setArguments(bundle);
return frag;
}
//...
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mRecyclerView.addOnItemTouchListener(this);
//...
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
switch (e.getAction()){
case MotionEvent.ACTION_DOWN:
originalFingerPos = e.getY();
break;
case MotionEvent.ACTION_MOVE:
if (e.getY() - originalFingerPos > TOUCH_SLOP){
if (hideMenuInterface != null) {
hideMenuInterface.onTouchEvent(FloatingButtonInterface.MOTION_DOWN);
} else {
Log.e(LOG_TAG, "hideMenuInterface is null");
}
} else if (e.getY() + TOUCH_SLOP < originalFingerPos ){
if (hideMenuInterface != null) {
hideMenuInterface.onTouchEvent(FloatingButtonInterface.MOTION_UP);
} else {
Log.e(LOG_TAG, "hideMenuInterface is null");
}
}
}
return false;
}
我遇到的主要问题与用户在更改配置后在屏幕上向上或向下滑动时用于自动隐藏按钮的代码有关。如果我在测试设备上更改屏幕方向,当我尝试通过滑动隐藏按钮时,一些 Fragments
没有响应,当我检查 LogCat
时,我可以看到 hideMenuInterface
是 null
。我能做些什么来解决这个问题?为什么它只影响一些片段而不是所有片段?如果我滑动到 ViewPager 中的最后一个片段然后再次返回,问题就会自行解决 - 可能是因为片段已被重新创建。
感谢您提供的任何见解!我只包含了我认为相关的代码,否则会有页面,但请询问您是否认为还有其他帮助。
我在 Android Developer docs 中找到了这个问题的答案。按照此页面上的说明操作后,按钮行为更加可靠。
编辑:
为了扩展我之前的回答,我通过以下方式应用了文档中的信息:
我通过添加一个名为 FloatingButtonInterface
的内部 interface
来更改 CategoryFragment
(占据每个 ViewPager
项目的片段),并为 [=15] 赋值=] onAttach()
期间的变量:
public class CategoryFragment extends Fragment implements RecyclerView.OnItemTouchListener {
//...
private static final int TOUCH_SLOP = 200;
private FloatingButtonInterface floatingButtonInterface;
//...
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
floatingButtonInterface = (FloatingButtonInterface) activity;
}
//...
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
originalFingerPos = e.getY();
return false;
case MotionEvent.ACTION_MOVE:
if (e.getY() - originalFingerPos > TOUCH_SLOP) {
floatingButtonInterface.onTouchEvent(FloatingButtonInterface.MOTION_DOWN);
return false;
} else if (e.getY() + TOUCH_SLOP < originalFingerPos) {
floatingButtonInterace.onTouchEvent(FloatingButtonInterface.MOTION_UP);
return false;
}
return false;
}
return false;
}
//...
public interface FloatingButtonInterface {
public static final int MOTION_UP = MOTION_NONE + 4;
public static final int MOTION_DOWN = MOTION_UP + 1;
public static final int MOTION_NONE = 0;
public void onTouchEvent(int callBackId);
}
唯一的其他变化是在 ViewPagerAdapter
内部。由于 CategoryFragment
负责分配接口,适配器中与此相关的任何代码都可以删除,因此适配器现在看起来像:
public class CategoriesViewPagerAdapter extends FragmentStatePagerAdapter {
private static final String LOG_TAG = "CategoriesViewPagerAd";
private Cursor mCursor;
private FloatingButtonInterface hideMenuInterface;
private FragmentManager mFragmentManager;
private boolean refreshItem = false;
public CategoriesViewPagerAdapter(FragmentManager fm, Cursor data) {
super(fm);
mCursor = data;
mFragmentManager = fm;
}
@Override
public Fragment getItem(int i) {
mCursor.moveToPosition(i);
int categoryFragmentIdentifier =
mCursor.getInt(mCursor.getColumnIndex(FilesDatabaseHelper.KEY_ID));
CategoryFragment frag = CategoryFragment.newInstance(categoryFragmentIdentifier);
return frag;
}