DrawerLayout是官方提供的侧滑菜单,相比SliddingMenu,它更加轻量级。默认情况下,DrawerLayout可以设置左侧或者右侧滑出菜单。如下,
xml布局:
- <!--
- <!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
- <com.sys.app.uikit.drawerlayoutplus.DrawerLayoutPlus xmlns:android="http://schemas.android.com/apk/res/android"
- android:id="@+id/drawer_layout"
- android:layout_width= "match_parent"
- android:layout_height= "match_parent" >
- <!--
- As the main content view, the view below consumes the entire
- space available using match_parent in both dimensions.
- -->
- <FrameLayout
- android:id="@+id/content_frame"
- android:layout_width="match_parent"
- android:layout_height="match_parent" />
- <!--
- android:layout_gravity="start" tells DrawerLayout to treat
- this as a sliding drawer on the left side for left-to-right
- languages and on the right side for right-to-left languages.
- The drawer is given a fixed width in dp and extends the full height of
- the container. A solid background is used for contrast
- with the content view.
- -->
- <!-- Left drawer -->
- <ListView
- android:id="@+id/left_drawer"
- android:layout_width="240dp"
- android:layout_height="match_parent"
- android:layout_gravity="left"
- android:background="#111"
- android:choiceMode="singleChoice"
- android:divider="@android:color/transparent"
- android:dividerHeight="0dp" />
- <!-- Right drawer -->
- <ListView
- android:id="@+id/right_drawer"
- android:layout_width="match_parent"
- android:layout_height="match_parent"
- android:layout_gravity="right"
- android:choiceMode="singleChoice" />
- </com.sys.app.uikit.drawerlayoutplus.DrawerLayoutPlus>
<!-- <!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<com.sys.app.uikit.drawerlayoutplus.DrawerLayoutPlus xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width= "match_parent"
android:layout_height= "match_parent" > <!--
As the main content view, the view below consumes the entire
space available using match_parent in both dimensions.
--> <FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" /> <!--
android:layout_gravity="start" tells DrawerLayout to treat
this as a sliding drawer on the left side for left-to-right
languages and on the right side for right-to-left languages.
The drawer is given a fixed width in dp and extends the full height of
the container. A solid background is used for contrast
with the content view.
--> <!-- Left drawer -->
<ListView
android:id="@+id/left_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="left"
android:background="#111"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp" /> <!-- Right drawer -->
<ListView
android:id="@+id/right_drawer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="right"
android:choiceMode="singleChoice" /> </com.sys.app.uikit.drawerlayoutplus.DrawerLayoutPlus>
Activity代码:
- package com.sys.app.uikit.drawerlayoutplus;
- import java.util.Locale;
- import android.app.Activity;
- import android.app.Fragment;
- import android.app.FragmentManager;
- import android.app.SearchManager;
- import android.content.Intent;
- import android.content.res.Configuration;
- import android.os.Bundle;
- import android.support.v4.view.GravityCompat;
- import android.view.LayoutInflater;
- import android.view.Menu;
- import android.view.MenuInflater;
- import android.view.MenuItem;
- import android.view.View;
- import android.view.ViewGroup;
- import android.widget.AdapterView;
- import android.widget.ArrayAdapter;
- import android.widget.ImageView;
- import android.widget.ListView;
- import android.widget.Toast;
- public class MainActivity extends Activity {
- private DrawerLayoutPlus mDrawerLayout;
- private ListView mLeftDrawerList, mRightDrawerList;
- private ActionBarDrawerToggle mDrawerToggle;
- private CharSequence mDrawerTitle;
- private CharSequence mTitle;
- private String[] mPlanetTitles;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- mTitle = mDrawerTitle = getTitle();
- mPlanetTitles = getResources().getStringArray(R.array.planets_array);
- mDrawerLayout = (DrawerLayoutPlus) findViewById(R.id.drawer_layout);
- mLeftDrawerList = (ListView) findViewById(R.id.left_drawer);
- mRightDrawerList = (ListView) findViewById(R.id.right_drawer);
- // set a custom shadow that overlays the main content when the drawer
- // opens
- mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
- // set up the drawer's list view with items and click listener
- mLeftDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mPlanetTitles));
- mLeftDrawerList.setOnItemClickListener(new DrawerItemClickListener());
- mRightDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mPlanetTitles));
- mRightDrawerList.setOnItemClickListener(new DrawerItemClickListener());
- // enable ActionBar app icon to behave as action to toggle nav drawer
- getActionBar().setDisplayHomeAsUpEnabled(true);
- getActionBar().setHomeButtonEnabled(true);
- // ActionBarDrawerToggle ties together the the proper interactions
- // between the sliding drawer and the action bar app icon
- mDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */
- mDrawerLayout, /* DrawerLayout object */
- R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
- R.string.drawer_open, /* "open drawer" description for accessibility */
- R.string.drawer_close /* "close drawer" description for accessibility */
- ) {
- public void onDrawerClosed(View view) {
- getActionBar().setTitle(mTitle);
- invalidateOptionsMenu(); // creates call to
- // onPrepareOptionsMenu()
- }
- public void onDrawerOpened(View drawerView) {
- getActionBar().setTitle(mDrawerTitle);
- invalidateOptionsMenu(); // creates call to
- // onPrepareOptionsMenu()
- }
- };
- mDrawerLayout.setDrawerListener(mDrawerToggle);
- if (savedInstanceState == null) {
- selectItem(0);
- }
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- MenuInflater inflater = getMenuInflater();
- inflater.inflate(R.menu.main, menu);
- return super.onCreateOptionsMenu(menu);
- }
- /* Called whenever we call invalidateOptionsMenu() */
- @Override
- public boolean onPrepareOptionsMenu(Menu menu) {
- // If the nav drawer is open, hide action items related to the content
- // view
- boolean drawerLeftOpen = mDrawerLayout.isDrawerOpen(mLeftDrawerList);
- boolean drawerRightOpen = mDrawerLayout.isDrawerOpen(mRightDrawerList);
- menu.findItem(R.id.action_websearch).setVisible(!(drawerLeftOpen && drawerRightOpen));
- return super.onPrepareOptionsMenu(menu);
- }
- @Override
- public boolean onOptionsItemSelected(MenuItem item) {
- // The action bar home/up action should open or close the drawer.
- // ActionBarDrawerToggle will take care of this.
- if (mDrawerToggle.onOptionsItemSelected(item)) {
- return true;
- }
- // Handle action buttons
- switch (item.getItemId()) {
- case R.id.action_websearch:
- // create intent to perform web search for this planet
- Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
- intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
- // catch event that there's no activity to handle intent
- if (intent.resolveActivity(getPackageManager()) != null) {
- startActivity(intent);
- } else {
- Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
- }
- return true;
- default:
- return super.onOptionsItemSelected(item);
- }
- }
- /* The click listner for ListView in the navigation drawer */
- private class DrawerItemClickListener implements ListView.OnItemClickListener {
- @Override
- public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
- selectItem(position);
- }
- }
- private void selectItem(int position) {
- // update the main content by replacing fragments
- Fragment fragment = new PlanetFragment();
- Bundle args = new Bundle();
- args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
- fragment.setArguments(args);
- FragmentManager fragmentManager = getFragmentManager();
- fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
- // update selected item and title, then close the drawer
- mLeftDrawerList.setItemChecked(position, true);
- mRightDrawerList.setItemChecked(position, true);
- setTitle(mPlanetTitles[position]);
- mDrawerLayout.closeDrawer(mLeftDrawerList);
- mDrawerLayout.closeDrawer(mRightDrawerList);
- }
- @Override
- public void setTitle(CharSequence title) {
- mTitle = title;
- getActionBar().setTitle(mTitle);
- }
- /**
- * When using the ActionBarDrawerToggle, you must call it during
- * onPostCreate() and onConfigurationChanged()...
- */
- @Override
- protected void onPostCreate(Bundle savedInstanceState) {
- super.onPostCreate(savedInstanceState);
- // Sync the toggle state after onRestoreInstanceState has occurred.
- mDrawerToggle.syncState();
- }
- @Override
- public void onConfigurationChanged(Configuration newConfig) {
- super.onConfigurationChanged(newConfig);
- // Pass any configuration change to the drawer toggls
- mDrawerToggle.onConfigurationChanged(newConfig);
- }
- /**
- * Fragment that appears in the "content_frame", shows a planet
- */
- public static class PlanetFragment extends Fragment {
- public static final String ARG_PLANET_NUMBER = "planet_number";
- public PlanetFragment() {
- // Empty constructor required for fragment subclasses
- }
- @Override
- public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
- View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
- int i = getArguments().getInt(ARG_PLANET_NUMBER);
- String planet = getResources().getStringArray(R.array.planets_array)[i];
- int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()), "drawable",
- getActivity().getPackageName());
- ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
- getActivity().setTitle(planet);
- return rootView;
- }
- }
- }
package com.sys.app.uikit.drawerlayoutplus; import java.util.Locale;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.SearchManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.view.GravityCompat;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast; public class MainActivity extends Activity { private DrawerLayoutPlus mDrawerLayout;
private ListView mLeftDrawerList, mRightDrawerList;
private ActionBarDrawerToggle mDrawerToggle; private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); mTitle = mDrawerTitle = getTitle();
mPlanetTitles = getResources().getStringArray(R.array.planets_array);
mDrawerLayout = (DrawerLayoutPlus) findViewById(R.id.drawer_layout);
mLeftDrawerList = (ListView) findViewById(R.id.left_drawer);
mRightDrawerList = (ListView) findViewById(R.id.right_drawer);
// set a custom shadow that overlays the main content when the drawer
// opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
mLeftDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mPlanetTitles));
mLeftDrawerList.setOnItemClickListener(new DrawerItemClickListener());
mRightDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mPlanetTitles));
mRightDrawerList.setOnItemClickListener(new DrawerItemClickListener()); // enable ActionBar app icon to behave as action to toggle nav drawer
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true); // ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to
// onPrepareOptionsMenu()
} public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to
// onPrepareOptionsMenu()
}
}; mDrawerLayout.setDrawerListener(mDrawerToggle); if (savedInstanceState == null) {
selectItem(0);
}
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
} /* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content
// view
boolean drawerLeftOpen = mDrawerLayout.isDrawerOpen(mLeftDrawerList);
boolean drawerRightOpen = mDrawerLayout.isDrawerOpen(mRightDrawerList);
menu.findItem(R.id.action_websearch).setVisible(!(drawerLeftOpen && drawerRightOpen));
return super.onPrepareOptionsMenu(menu);
} @Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch (item.getItemId()) {
case R.id.action_websearch:
// create intent to perform web search for this planet
Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
// catch event that there's no activity to handle intent
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
} else {
Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
} /* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
} private void selectItem(int position) {
// update the main content by replacing fragments
Fragment fragment = new PlanetFragment();
Bundle args = new Bundle();
args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
fragment.setArguments(args); FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit(); // update selected item and title, then close the drawer
mLeftDrawerList.setItemChecked(position, true);
mRightDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mLeftDrawerList);
mDrawerLayout.closeDrawer(mRightDrawerList);
} @Override
public void setTitle(CharSequence title) {
mTitle = title;
getActionBar().setTitle(mTitle);
} /**
* When using the ActionBarDrawerToggle, you must call it during
* onPostCreate() and onConfigurationChanged()...
*/ @Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
} @Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
} /**
* Fragment that appears in the "content_frame", shows a planet
*/
public static class PlanetFragment extends Fragment {
public static final String ARG_PLANET_NUMBER = "planet_number"; public PlanetFragment() {
// Empty constructor required for fragment subclasses
} @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
int i = getArguments().getInt(ARG_PLANET_NUMBER);
String planet = getResources().getStringArray(R.array.planets_array)[i]; int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()), "drawable",
getActivity().getPackageName());
((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
getActivity().setTitle(planet);
return rootView;
}
}
}
效果如图所示:
图-1
如果换一个需求,是从下面弹出菜单,那是用系统的DrawerLayout是做不到的,不过可以通过修改其源码来达到目的。
二、分析
DrawerLayout作为一个父类容器,可以包含子View,而子View又可以分为内容区域和菜单区域。内容区域占据整个屏幕大小,菜单区域默认在屏幕内侧。DrawerLayout继承于ViewGroup,必然需要重写onLayout()方法,那么在设置子View位置的时候,内容区域默认直接显示出来,菜单区域默认隐藏在屏幕内侧。DrawerLayout的onLayout()代码如下:
- @Override
- protected void onLayout(boolean changed, int l, int t, int r, int b) {
- mInLayout = true ;
- final int width = r - l;
- final int childCount = getChildCount();
- for (int i = 0; i < childCount; i++) {
- final View child = getChildAt(i);
- if (child.getVisibility() == GONE) {
- continue;
- }
- final LayoutParams lp = (LayoutParams) child.getLayoutParams();
- if (isContentView(child)) {
- child.layout(lp. leftMargin, lp.topMargin, lp.leftMargin + child.getMeasuredWidth(),
- lp. topMargin + child.getMeasuredHeight());
- } else { // Drawer, if it wasn't onMeasure would have thrown an
- // exception.
- final int childWidth = child.getMeasuredWidth();
- final int childHeight = child.getMeasuredHeight();
- int childLeft;
- final float newOffset;
- if (checkDrawerViewAbsoluteGravity(child, Gravity.LEFT)) {
- childLeft = -childWidth + ( int) (childWidth * lp.onScreen);
- newOffset = ( float) (childWidth + childLeft) / childWidth;
- } else { // Right; onMeasure checked for us.
- childLeft = width - ( int) (childWidth * lp.onScreen);
- newOffset = ( float) (width - childLeft) / childWidth;
- }
- final boolean changeOffset = newOffset != lp.onScreen;
- final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK ;
- switch (vgrav) {
- default:
- case Gravity.TOP : {
- child.layout(childLeft, lp.topMargin, childLeft + childWidth, lp.topMargin + childHeight);
- break;
- }
- case Gravity.BOTTOM : {
- final int height = b - t;
- child.layout(childLeft, height - lp.bottomMargin - child.getMeasuredHeight(), childLeft + childWidth,
- height - lp.bottomMargin);
- break;
- }
- case Gravity.CENTER_VERTICAL : {
- final int height = b - t;
- int childTop = (height - childHeight) / 2;
- // Offset for margins. If things don't fit right because of
- // bad measurement before, oh well.
- if (childTop < lp.topMargin ) {
- childTop = lp. topMargin;
- } else if (childTop + childHeight > height - lp.bottomMargin ) {
- childTop = height - lp.bottomMargin - childHeight;
- }
- child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
- break;
- }
- }
- if (changeOffset) {
- setDrawerViewOffset(child, newOffset);
- }
- final int newVisibility = lp.onScreen > 0 ? VISIBLE : INVISIBLE ;
- if (child.getVisibility() != newVisibility) {
- child.setVisibility(newVisibility);
- }
- }
- }
- mInLayout = false ;
- mFirstLayout = false ;
- }
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
mInLayout = true ;
final int width = r - l;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i); if (child.getVisibility() == GONE) {
continue;
} final LayoutParams lp = (LayoutParams) child.getLayoutParams(); if (isContentView(child)) {
child.layout(lp. leftMargin, lp.topMargin, lp.leftMargin + child.getMeasuredWidth(),
lp. topMargin + child.getMeasuredHeight());
} else { // Drawer, if it wasn't onMeasure would have thrown an
// exception.
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
int childLeft; final float newOffset;
if (checkDrawerViewAbsoluteGravity(child, Gravity.LEFT)) {
childLeft = -childWidth + ( int) (childWidth * lp.onScreen);
newOffset = ( float) (childWidth + childLeft) / childWidth;
} else { // Right; onMeasure checked for us.
childLeft = width - ( int) (childWidth * lp.onScreen);
newOffset = ( float) (width - childLeft) / childWidth;
} final boolean changeOffset = newOffset != lp.onScreen; final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK ;
switch (vgrav) {
default:
case Gravity.TOP : {
child.layout(childLeft, lp.topMargin, childLeft + childWidth, lp.topMargin + childHeight);
break;
} case Gravity.BOTTOM : {
final int height = b - t;
child.layout(childLeft, height - lp.bottomMargin - child.getMeasuredHeight(), childLeft + childWidth,
height - lp.bottomMargin);
break;
} case Gravity.CENTER_VERTICAL : {
final int height = b - t;
int childTop = (height - childHeight) / 2; // Offset for margins. If things don't fit right because of
// bad measurement before, oh well.
if (childTop < lp.topMargin ) {
childTop = lp. topMargin;
} else if (childTop + childHeight > height - lp.bottomMargin ) {
childTop = height - lp.bottomMargin - childHeight;
}
child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
break;
}
} if (changeOffset) {
setDrawerViewOffset(child, newOffset);
} final int newVisibility = lp.onScreen > 0 ? VISIBLE : INVISIBLE ;
if (child.getVisibility() != newVisibility) {
child.setVisibility(newVisibility);
}
}
}
mInLayout = false ;
mFirstLayout = false ;
}
在onLayout方法中可以通过参数获取之前测量DrawerLayout的宽度和高度,然后获取DrawerLayout里面子View的个数,通过一个for循环来设置子View的位置。可以看到先是设置内容区域的位置,然后是菜单区域,后者通过设置offset来达到隐藏菜单的目的。所以这个地方是关键,如果想要在屏幕下方弹出菜单,那么就需要修改菜单的显示位置,让它置于屏幕下方。
菜单View位置更改好,接着是手势操作的部分。在DrawerLayout中,是通过ViewDragHelper这个类来实现View的拖拽。首先它声明了左右菜单的帮助类和回调,
- private final ViewDragHelper mLeftDragger ;
- private final ViewDragHelper mRightDragger ;
- private final ViewDragCallback mLeftCallback ;
- private final ViewDragCallback mRightCallback ;
private final ViewDragHelper mLeftDragger ;
private final ViewDragHelper mRightDragger ;
private final ViewDragCallback mLeftCallback ;
private final ViewDragCallback mRightCallback ;
以及左右锁和阴影,
- private int mLockModeLeft ;
- private int mLockModeRight ;
- private Drawable mShadowLeft ;
- private Drawable mShadowRight ;
private int mLockModeLeft ;
private int mLockModeRight ; private Drawable mShadowLeft ;
private Drawable mShadowRight ;
在构造方法里面初始化了帮助类和回调,
- mLeftCallback = new ViewDragCallback(Gravity.LEFT );
- mRightCallback = new ViewDragCallback(Gravity.RIGHT );
- mLeftDragger = ViewDragHelper.create( this , TOUCH_SLOP_SENSITIVITY , mLeftCallback );
- mLeftDragger .setEdgeTrackingEnabled(ViewDragHelper. EDGE_LEFT);
- mLeftDragger .setMinVelocity(minVel);
- mLeftCallback .setDragger(mLeftDragger );
- mRightDragger = ViewDragHelper.create( this , TOUCH_SLOP_SENSITIVITY , mRightCallback );
- mRightDragger .setEdgeTrackingEnabled(ViewDragHelper. EDGE_RIGHT);
- mRightDragger .setMinVelocity(minVel);
- mRightCallback .setDragger(mRightDragger );
mLeftCallback = new ViewDragCallback(Gravity.LEFT );
mRightCallback = new ViewDragCallback(Gravity.RIGHT ); mLeftDragger = ViewDragHelper.create( this , TOUCH_SLOP_SENSITIVITY , mLeftCallback );
mLeftDragger .setEdgeTrackingEnabled(ViewDragHelper. EDGE_LEFT);
mLeftDragger .setMinVelocity(minVel);
mLeftCallback .setDragger(mLeftDragger ); mRightDragger = ViewDragHelper.create( this , TOUCH_SLOP_SENSITIVITY , mRightCallback );
mRightDragger .setEdgeTrackingEnabled(ViewDragHelper. EDGE_RIGHT);
mRightDragger .setMinVelocity(minVel);
mRightCallback .setDragger(mRightDragger );
在设置阴影效果,进行一个左右的判断
- public void setDrawerShadow(Drawable shadowDrawable, @EdgeGravity int gravity) {
- /*
- * TODO Someone someday might want to set more complex drawables here.
- * They're probably nuts, but we might want to consider registering
- * callbacks, setting states, etc. properly.
- */
- final int absGravity = GravityCompat.getAbsoluteGravity(gravity, ViewCompat.getLayoutDirection( this));
- if ((absGravity & Gravity. LEFT) == Gravity. LEFT) {
- mShadowLeft = shadowDrawable;
- invalidate();
- }
- if ((absGravity & Gravity. RIGHT) == Gravity.RIGHT ) {
- mShadowRight = shadowDrawable;
- invalidate();
- }
- }
public void setDrawerShadow(Drawable shadowDrawable, @EdgeGravity int gravity) {
/*
* TODO Someone someday might want to set more complex drawables here.
* They're probably nuts, but we might want to consider registering
* callbacks, setting states, etc. properly.
*/ final int absGravity = GravityCompat.getAbsoluteGravity(gravity, ViewCompat.getLayoutDirection( this));
if ((absGravity & Gravity. LEFT) == Gravity. LEFT) {
mShadowLeft = shadowDrawable;
invalidate();
}
if ((absGravity & Gravity. RIGHT) == Gravity.RIGHT ) {
mShadowRight = shadowDrawable;
invalidate();
}
}
还有菜单锁,
- public void setDrawerLockMode(@LockMode int lockMode) {
- setDrawerLockMode(lockMode, Gravity. LEFT );
- setDrawerLockMode(lockMode, Gravity. RIGHT );
- }
public void setDrawerLockMode(@LockMode int lockMode) {
setDrawerLockMode(lockMode, Gravity. LEFT );
setDrawerLockMode(lockMode, Gravity. RIGHT );
}
也是进行左右的判断,
- public void setDrawerLockMode(@LockMode int lockMode, @EdgeGravity int edgeGravity) {
- final int absGravity = GravityCompat.getAbsoluteGravity(edgeGravity, ViewCompat.getLayoutDirection( this));
- if (absGravity == Gravity. LEFT) {
- mLockModeLeft = lockMode;
- } else if (absGravity == Gravity. RIGHT) {
- mLockModeRight = lockMode;
- }
- if (lockMode != LOCK_MODE_UNLOCKED) {
- // Cancel interaction in progress
- final ViewDragHelper helper = absGravity == Gravity.LEFT ? mLeftDragger : mRightDragger ;
- helper.cancel();
- }
- switch (lockMode) {
- case LOCK_MODE_LOCKED_OPEN :
- final View toOpen = findDrawerWithGravity(absGravity);
- if (toOpen != null) {
- openDrawer(toOpen);
- }
- break ;
- case LOCK_MODE_LOCKED_CLOSED :
- final View toClose = findDrawerWithGravity(absGravity);
- if (toClose != null) {
- closeDrawer(toClose);
- }
- break ;
- // default: do nothing
- }
- }
public void setDrawerLockMode(@LockMode int lockMode, @EdgeGravity int edgeGravity) {
final int absGravity = GravityCompat.getAbsoluteGravity(edgeGravity, ViewCompat.getLayoutDirection( this));
if (absGravity == Gravity. LEFT) {
mLockModeLeft = lockMode;
} else if (absGravity == Gravity. RIGHT) {
mLockModeRight = lockMode;
}
if (lockMode != LOCK_MODE_UNLOCKED) {
// Cancel interaction in progress
final ViewDragHelper helper = absGravity == Gravity.LEFT ? mLeftDragger : mRightDragger ;
helper.cancel();
}
switch (lockMode) {
case LOCK_MODE_LOCKED_OPEN :
final View toOpen = findDrawerWithGravity(absGravity);
if (toOpen != null) {
openDrawer(toOpen);
}
break ;
case LOCK_MODE_LOCKED_CLOSED :
final View toClose = findDrawerWithGravity(absGravity);
if (toClose != null) {
closeDrawer(toClose);
}
break ;
// default: do nothing
}
}
不光是上面的方法,DrawerLayout中还有很多方法也都是这样。都是对Gravity的判断,判断是左侧菜单还是右侧,所以如果要改成从底部弹出菜单,那么把相应的值替换为Gravity.BOTTOM即可。当然还要注意在替换的过程中的一些逻辑问题,以免有纰漏。比如offset之前是左右,现在要改成上下,因此数值要重新计算。还有变量的命名等,之前是left或者right,现在改为bottom等等。
修改后运行效果如下: