AlertDialog源码分析
2018-05-18 本文已影响50人
Android_冯星
基本使用
使用非常简单，典型的建造者模式。
new AlertDialog.Builder(this)
.setIcon(R.drawable.ic_launcher_background)
.setTitle("测试AlertDialog")
.setMessage("源码分析中。。。")
.setNegativeButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
})
.setPositiveButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).create().show();
AlertDialog继承Dialog实现了DialogInterface
public class AlertDialog extends Dialog implements DialogInterface {
DialogInterface
DialogInterface接口中定义了对话框的一些事件
/**
* Interface that defines a dialog-type class that can be shown, dismissed, or
* canceled, and may have buttons that can be clicked.
*/
public interface DialogInterface {
/** The identifier for the positive button. */
int BUTTON_POSITIVE = -1;
/** The identifier for the negative button. */
int BUTTON_NEGATIVE = -2;
/** The identifier for the neutral button. */
int BUTTON_NEUTRAL = -3;
/** @deprecated Use {@link #BUTTON_POSITIVE} */
@Deprecated
int BUTTON1 = BUTTON_POSITIVE;
/** @deprecated Use {@link #BUTTON_NEGATIVE} */
@Deprecated
int BUTTON2 = BUTTON_NEGATIVE;
/** @deprecated Use {@link #BUTTON_NEUTRAL} */
@Deprecated
int BUTTON3 = BUTTON_NEUTRAL;
/**
* Cancels the dialog, invoking the {@link OnCancelListener}.
* <p>
* The {@link OnDismissListener} may also be called if cancellation
* dismisses the dialog.
*/
void cancel();
/**
* Dismisses the dialog, invoking the {@link OnDismissListener}.
*/
void dismiss();
/**
* Interface used to allow the creator of a dialog to run some code when the
* dialog is canceled.
* <p>
* This will only be called when the dialog is canceled, if the creator
* needs to know when it is dismissed in general, use
* {@link DialogInterface.OnDismissListener}.
*/
interface OnCancelListener {
/**
* This method will be invoked when the dialog is canceled.
*
* @param dialog the dialog that was canceled will be passed into the
* method
*/
void onCancel(DialogInterface dialog);
}
/**
* Interface used to allow the creator of a dialog to run some code when the
* dialog is dismissed.
*/
interface OnDismissListener {
/**
* This method will be invoked when the dialog is dismissed.
*
* @param dialog the dialog that was dismissed will be passed into the
* method
*/
void onDismiss(DialogInterface dialog);
}
/**
* Interface used to allow the creator of a dialog to run some code when the
* dialog is shown.
*/
interface OnShowListener {
/**
* This method will be invoked when the dialog is shown.
*
* @param dialog the dialog that was shown will be passed into the
* method
*/
void onShow(DialogInterface dialog);
}
/**
* Interface used to allow the creator of a dialog to run some code when an
* item on the dialog is clicked.
*/
interface OnClickListener {
/**
* This method will be invoked when a button in the dialog is clicked.
*
* @param dialog the dialog that received the click
* @param which the button that was clicked (ex.
* {@link DialogInterface#BUTTON_POSITIVE}) or the position
* of the item clicked
*/
void onClick(DialogInterface dialog, int which);
}
/**
* Interface used to allow the creator of a dialog to run some code when an
* item in a multi-choice dialog is clicked.
*/
interface OnMultiChoiceClickListener {
/**
* This method will be invoked when an item in the dialog is clicked.
*
* @param dialog the dialog where the selection was made
* @param which the position of the item in the list that was clicked
* @param isChecked {@code true} if the click checked the item, else
* {@code false}
*/
void onClick(DialogInterface dialog, int which, boolean isChecked);
}
/**
* Interface definition for a callback to be invoked when a key event is
* dispatched to this dialog. The callback will be invoked before the key
* event is given to the dialog.
*/
interface OnKeyListener {
/**
* Called when a key is dispatched to a dialog. This allows listeners to
* get a chance to respond before the dialog.
*
* @param dialog the dialog the key has been dispatched to
* @param keyCode the code for the physical key that was pressed
* @param event the KeyEvent object containing full information about
* the event
* @return {@code true} if the listener has consumed the event,
* {@code false} otherwise
*/
boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event);
}
}
方法和接口
-
void cancel();
取消对话框，如果执行cancel方法，会执行OnCancelListener接口，也会执行OnDismissListener接口。取消的是对话框的行为。让对话消失请使用dismiss -
void dismiss();
接触对话框，如果被调用会执行OnDismissListener接口。 -
interface OnCancelListener
OnCancelListener接口，如果 cancel()方法被调用时执行这个方法。 -
interface OnDismissListener
在对话框消失时，允许用户做一些做操。 -
interface OnShowListener
显示对话框调用此方法 -
interface OnClickListener
-
interface OnMultiChoiceClickListener
用于在单击多选对话框中的项目时允许对话创建者运行某些代码的界面。 -
interface OnKeyListener
当按键盘时会调用
使用
AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this)
.setIcon(R.drawable.ic_launcher_background)
.setTitle("测试AlertDialog")
.setMessage("源码分析中。。。")
.setNegativeButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
})
.setPositiveButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).create();
alertDialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
Log.d(TAG, "onKey: " + dialog);
Log.d(TAG, "onKey: " + keyCode);
Log.d(TAG, "onKey: " + event.toString());
return false;
}
});
alertDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
Log.d(TAG, "onCancel: " + dialog.toString());
}
});
alertDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
Log.d(TAG, "onDismiss: " + dialog.toString());
}
});
alertDialog.setOnShowListener(new DialogInterface.OnShowListener() {
@Override
public void onShow(DialogInterface dialog) {
Log.d(TAG, "onShow: " + dialog.toString());
}
});
alertDialog.show();
结果
05-14 14:40:45.679 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onShow: android.app.AlertDialog@273ca78
05-14 14:40:51.220 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onDismiss: android.app.AlertDialog@273ca78
05-14 14:40:54.277 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onShow: android.app.AlertDialog@5624c4a
05-14 14:40:55.808 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onDismiss: android.app.AlertDialog@5624c4a
05-14 14:41:04.338 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onShow: android.app.AlertDialog@7183a4c
05-14 14:41:06.027 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onCancel: android.app.AlertDialog@7183a4c
05-14 14:41:06.030 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onDismiss: android.app.AlertDialog@7183a4c
05-14 14:41:13.671 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onShow: android.app.AlertDialog@a0a6dbd
05-14 14:41:15.847 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: android.app.AlertDialog@a0a6dbd
05-14 14:41:15.847 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: 4
05-14 14:41:15.847 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: KeyEvent { action=ACTION_DOWN, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x8, hwFlags=0x0, repeatCount=0, eventTime=260202524, downTime=260202524, deviceId=0, source=0x101 }
05-14 14:41:15.849 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: android.app.AlertDialog@a0a6dbd
05-14 14:41:15.849 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: 4
05-14 14:41:15.850 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onKey: KeyEvent { action=ACTION_UP, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x8, hwFlags=0x0, repeatCount=0, eventTime=260202525, downTime=260202525, deviceId=0, source=0x101 }
05-14 14:41:15.888 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onCancel: android.app.AlertDialog@a0a6dbd
05-14 14:41:15.889 9285-9285/com.fengxing.mcp.fdialog D/MainActivity: onDismiss: android.app.AlertDialog@a0a6dbd
结果显示出 点击onCancel事件自动调用onDismiss事件。
AlertDialog
创建对话框有两种形式：
- 利用AlertDialog创建对话框
- 用AlertDialog.Builder创建对话框
使用AlertDialog创建对话框，设置的参数如标题，信息，按钮会存放在AlertController类中。
使用AlertDialog.Builder创建对话框，参数信息存放在AlertController.AlertParams静态内部类中。
代码
AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this)
// .setIcon(R.drawable.ic_launcher_background)
// .setTitle("测试AlertDialog")
// .setMessage("源码分析中。。。")
// .setNegativeButton("确定", new DialogInterface.OnClickListener() {
// @Override
// public void onClick(DialogInterface dialog, int which) {
//
// }
// })
// .setPositiveButton("取消", new DialogInterface.OnClickListener() {
// @Override
// public void onClick(DialogInterface dialog, int which) {
// dialog.dismiss();
// }
// })
// .setNeutralButton("按钮", new DialogInterface.OnClickListener() {
// @Override
// public void onClick(DialogInterface dialog, int which) {
// Toast.makeText(MainActivity.this,"点击第三个按钮",Toast.LENGTH_LONG).show();
// }
// })
.create();
alertDialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
Log.d(TAG, "onKey: " + dialog);
Log.d(TAG, "onKey: " + keyCode);
Log.d(TAG, "onKey: " + event.toString());
return false;
}
});
alertDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
Log.d(TAG, "onCancel: " + dialog.toString());
}
});
alertDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
Log.d(TAG, "onDismiss: " + dialog.toString());
}
});
alertDialog.setOnShowListener(new DialogInterface.OnShowListener() {
@Override
public void onShow(DialogInterface dialog) {
Log.d(TAG, "onShow: " + dialog.toString());
}
});
//另一种形式
alertDialog.setTitle("对话框标题");
alertDialog.setIcon(R.drawable.ic_launcher_foreground);
alertDialog.setMessage("对话框内容");
alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, "888", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
alertDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "999", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
Button button = alertDialog.getButton(DialogInterface.BUTTON_POSITIVE);
if (button != null) {
button.setText("更改");
}
alertDialog.setButton(DialogInterface.BUTTON_NEUTRAL, "第三个按钮", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
alertDialog.show();
AlertDialog类中主要是一些设置对话框的方法如下：
-
resolveDialogTheme
设置对话框的主题 -
getButton
获取按钮 确定 取消 中性 用DialogInterface中定义的按钮获取。BUTTON_POSITIVE，BUTTON_NEGATIVE，BUTTON_NEUTRAL -
getListView 获取dialog使用的listView
-
setTitle
-
setCustomTitle
-
setMessage
-
setView
-
setButton
-
setIcon
-
setIconAttribute
都是设置参数的方法，以setMessage为例:
setMessage源码：
public void setMessage(CharSequence message) {
mAlert.setMessage(message);
}
mAlert是如何创建的？
在创建AlertDialog中会创建mAlert。
AlertDialog(Context context, @StyleRes int themeResId, boolean createContextThemeWrapper) {
super(context, createContextThemeWrapper ? resolveDialogTheme(context, themeResId) : 0,
createContextThemeWrapper);
mWindow.alwaysReadCloseOnTouchAttr();
mAlert = AlertController.create(getContext(), this, getWindow());
}
AlertController.create(getContext(), this, getWindow())方法中传入上下文，AlertDialog，和Window窗口。这个window窗口其实是
final Window w = new PhoneWindow(mContext);PhoneWindow是在Dialog类构造函数中生成的。
public static final AlertController create(Context context, DialogInterface di, Window window) {
final TypedArray a = context.obtainStyledAttributes(
null, R.styleable.AlertDialog, R.attr.alertDialogStyle, 0);
int controllerType = a.getInt(R.styleable.AlertDialog_controllerType, 0);
a.recycle();
switch (controllerType) {
case MICRO:
return new MicroAlertController(context, di, window);
default:
return new AlertController(context, di, window);
}
}
根据AlertDialog_controllerType的值，决定使用哪个AlertController。MicroAlertController继承AlertController。重写了setupContent setupTitle setupButtons方法。应该matrix风格的。
在AlertDialog中设置了一些参数。这些参数都被存放在AlertController中，然后被AlertController使用。贴出几个典型的代码
public void setTitle(CharSequence title) {
mTitle = title;
if (mTitleView != null) {
mTitleView.setText(title);
}
}
public void setMessage(CharSequence message) {
mMessage = message;
if (mMessageView != null) {
mMessageView.setText(message);
}
}
创建Dialog视图
AlertController中比较重要的方法installContent。这个方法是创建dialog视图的。根据创建Dialog的方式不同 调用的方法也不同。（Builder模式创建和AlertDialog创建）。
public void installContent(AlertParams params) {
params.apply(this);
installContent();
}
public void installContent() {
int contentView = selectContentView();
mWindow.setContentView(contentView);
setupView();
}
public void installContent()这个方法是在AlertDialog类中onCreate方法中调用的。继续网上跟踪。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mAlert.installContent();
}
AlertDialog继承Dialog，也重写了onCreate方法，查看Dialog类中的onCreate是在什么时候调用。
// internal method to make sure mCreated is set properly without requiring
// users to call through to super in onCreate
void dispatchOnCreate(Bundle savedInstanceState) {
if (!mCreated) {
onCreate(savedInstanceState);
mCreated = true;
}
}
在show方法执行时，添加视图，展示对话框。
/**
* Start the dialog and display it on screen. The window is placed in the
* application layer and opaque. Note that you should not override this
* method to do initialization when the dialog is shown, instead implement
* that in {@link #onStart}.
*/
public void show() {
if (mShowing) {
if (mDecor != null) {
if (mWindow.hasFeature(Window.FEATURE_ACTION_BAR)) {
mWindow.invalidatePanelMenu(Window.FEATURE_ACTION_BAR);
}
mDecor.setVisibility(View.VISIBLE);
}
return;
}
mCanceled = false;
if (!mCreated) {
dispatchOnCreate(null);
} else {
// Fill the DecorView in on any configuration changes that
// may have occured while it was removed from the WindowManager.
final Configuration config = mContext.getResources().getConfiguration();
mWindow.getDecorView().dispatchConfigurationChanged(config);
}
onStart();
mDecor = mWindow.getDecorView();
if (mActionBar == null && mWindow.hasFeature(Window.FEATURE_ACTION_BAR)) {
final ApplicationInfo info = mContext.getApplicationInfo();
mWindow.setDefaultIcon(info.icon);
mWindow.setDefaultLogo(info.logo);
mActionBar = new WindowDecorActionBar(this);
}
WindowManager.LayoutParams l = mWindow.getAttributes();
if ((l.softInputMode
& WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION) == 0) {
WindowManager.LayoutParams nl = new WindowManager.LayoutParams();
nl.copyFrom(l);
nl.softInputMode |=
WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION;
l = nl;
}
mWindowManager.addView(mDecor, l);
mShowing = true;
sendShowMessage();
}
AlertController剩下其它比较重要的就是添加Layout视图，
private int selectContentView() {
if (mButtonPanelSideLayout == 0) {
return mAlertDialogLayout;
}
if (mButtonPanelLayoutHint == AlertDialog.LAYOUT_HINT_SIDE) {
return mButtonPanelSideLayout;
}
// TODO: use layout hint side for long messages/lists
return mAlertDialogLayout;
}
添加显示内容，标题，按钮，显示位置，以及背景。
private void setupView() {
final View parentPanel = mWindow.findViewById(R.id.parentPanel);
final View defaultTopPanel = parentPanel.findViewById(R.id.topPanel);
final View defaultContentPanel = parentPanel.findViewById(R.id.contentPanel);
final View defaultButtonPanel = parentPanel.findViewById(R.id.buttonPanel);
// Install custom content before setting up the title or buttons so
// that we can handle panel overrides.
final ViewGroup customPanel = (ViewGroup) parentPanel.findViewById(R.id.customPanel);
setupCustomContent(customPanel);
final View customTopPanel = customPanel.findViewById(R.id.topPanel);
final View customContentPanel = customPanel.findViewById(R.id.contentPanel);
final View customButtonPanel = customPanel.findViewById(R.id.buttonPanel);
// Resolve the correct panels and remove the defaults, if needed.
final ViewGroup topPanel = resolvePanel(customTopPanel, defaultTopPanel);
final ViewGroup contentPanel = resolvePanel(customContentPanel, defaultContentPanel);
final ViewGroup buttonPanel = resolvePanel(customButtonPanel, defaultButtonPanel);
setupContent(contentPanel);
setupButtons(buttonPanel);
setupTitle(topPanel);
final boolean hasCustomPanel = customPanel != null
&& customPanel.getVisibility() != View.GONE;
final boolean hasTopPanel = topPanel != null
&& topPanel.getVisibility() != View.GONE;
final boolean hasButtonPanel = buttonPanel != null
&& buttonPanel.getVisibility() != View.GONE;
// Only display the text spacer if we don't have buttons.
if (!hasButtonPanel) {
if (contentPanel != null) {
final View spacer = contentPanel.findViewById(R.id.textSpacerNoButtons);
if (spacer != null) {
spacer.setVisibility(View.VISIBLE);
}
}
mWindow.setCloseOnTouchOutsideIfNotSet(true);
}
if (hasTopPanel) {
// Only clip scrolling content to padding if we have a title.
if (mScrollView != null) {
mScrollView.setClipToPadding(true);
}
// Only show the divider if we have a title.
View divider = null;
if (mMessage != null || mListView != null || hasCustomPanel) {
if (!hasCustomPanel) {
divider = topPanel.findViewById(R.id.titleDividerNoCustom);
}
if (divider == null) {
divider = topPanel.findViewById(R.id.titleDivider);
}
} else {
divider = topPanel.findViewById(R.id.titleDividerTop);
}
if (divider != null) {
divider.setVisibility(View.VISIBLE);
}
} else {
if (contentPanel != null) {
final View spacer = contentPanel.findViewById(R.id.textSpacerNoTitle);
if (spacer != null) {
spacer.setVisibility(View.VISIBLE);
}
}
}
if (mListView instanceof RecycleListView) {
((RecycleListView) mListView).setHasDecor(hasTopPanel, hasButtonPanel);
}
// Update scroll indicators as needed.
if (!hasCustomPanel) {
final View content = mListView != null ? mListView : mScrollView;
if (content != null) {
final int indicators = (hasTopPanel ? View.SCROLL_INDICATOR_TOP : 0)
| (hasButtonPanel ? View.SCROLL_INDICATOR_BOTTOM : 0);
content.setScrollIndicators(indicators,
View.SCROLL_INDICATOR_TOP | View.SCROLL_INDICATOR_BOTTOM);
}
}
final TypedArray a = mContext.obtainStyledAttributes(
null, R.styleable.AlertDialog, R.attr.alertDialogStyle, 0);
setBackground(a, topPanel, contentPanel, customPanel, buttonPanel,
hasTopPanel, hasCustomPanel, hasButtonPanel);
a.recycle();
}
private void setupCustomContent(ViewGroup customPanel) {
final View customView;
if (mView != null) {
customView = mView;
} else if (mViewLayoutResId != 0) {
final LayoutInflater inflater = LayoutInflater.from(mContext);
customView = inflater.inflate(mViewLayoutResId, customPanel, false);
} else {
customView = null;
}
final boolean hasCustomView = customView != null;
if (!hasCustomView || !canTextInput(customView)) {
mWindow.setFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM,
WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);
}
if (hasCustomView) {
final FrameLayout custom = (FrameLayout) mWindow.findViewById(R.id.custom);
custom.addView(customView, new LayoutParams(MATCH_PARENT, MATCH_PARENT));
if (mViewSpacingSpecified) {
custom.setPadding(
mViewSpacingLeft, mViewSpacingTop, mViewSpacingRight, mViewSpacingBottom);
}
if (mListView != null) {
((LinearLayout.LayoutParams) customPanel.getLayoutParams()).weight = 0;
}
} else {
customPanel.setVisibility(View.GONE);
}
}
protected void setupTitle(ViewGroup topPanel) {
if (mCustomTitleView != null && mShowTitle) {
// Add the custom title view directly to the topPanel layout
final LayoutParams lp = new LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
topPanel.addView(mCustomTitleView, 0, lp);
// Hide the title template
final View titleTemplate = mWindow.findViewById(R.id.title_template);
titleTemplate.setVisibility(View.GONE);
} else {
mIconView = (ImageView) mWindow.findViewById(R.id.icon);
final boolean hasTextTitle = !TextUtils.isEmpty(mTitle);
if (hasTextTitle && mShowTitle) {
// Display the title if a title is supplied, else hide it.
mTitleView = (TextView) mWindow.findViewById(R.id.alertTitle);
mTitleView.setText(mTitle);
// Do this last so that if the user has supplied any icons we
// use them instead of the default ones. If the user has
// specified 0 then make it disappear.
if (mIconId != 0) {
mIconView.setImageResource(mIconId);
} else if (mIcon != null) {
mIconView.setImageDrawable(mIcon);
} else {
// Apply the padding from the icon to ensure the title is
// aligned correctly.
mTitleView.setPadding(mIconView.getPaddingLeft(),
mIconView.getPaddingTop(),
mIconView.getPaddingRight(),
mIconView.getPaddingBottom());
mIconView.setVisibility(View.GONE);
}
} else {
// Hide the title template
final View titleTemplate = mWindow.findViewById(R.id.title_template);
titleTemplate.setVisibility(View.GONE);
mIconView.setVisibility(View.GONE);
topPanel.setVisibility(View.GONE);
}
}
}
protected void setupContent(ViewGroup contentPanel) {
mScrollView = (ScrollView) contentPanel.findViewById(R.id.scrollView);
mScrollView.setFocusable(false);
// Special case for users that only want to display a String
mMessageView = (TextView) contentPanel.findViewById(R.id.message);
if (mMessageView == null) {
return;
}
if (mMessage != null) {
mMessageView.setText(mMessage);
} else {
mMessageView.setVisibility(View.GONE);
mScrollView.removeView(mMessageView);
if (mListView != null) {
final ViewGroup scrollParent = (ViewGroup) mScrollView.getParent();
final int childIndex = scrollParent.indexOfChild(mScrollView);
scrollParent.removeViewAt(childIndex);
scrollParent.addView(mListView, childIndex,
new LayoutParams(MATCH_PARENT, MATCH_PARENT));
} else {
contentPanel.setVisibility(View.GONE);
}
}
}
private static void manageScrollIndicators(View v, View upIndicator, View downIndicator) {
if (upIndicator != null) {
upIndicator.setVisibility(v.canScrollVertically(-1) ? View.VISIBLE : View.INVISIBLE);
}
if (downIndicator != null) {
downIndicator.setVisibility(v.canScrollVertically(1) ? View.VISIBLE : View.INVISIBLE);
}
}
protected void setupButtons(ViewGroup buttonPanel) {
int BIT_BUTTON_POSITIVE = 1;
int BIT_BUTTON_NEGATIVE = 2;
int BIT_BUTTON_NEUTRAL = 4;
int whichButtons = 0;
mButtonPositive = (Button) buttonPanel.findViewById(R.id.button1);
mButtonPositive.setOnClickListener(mButtonHandler);
if (TextUtils.isEmpty(mButtonPositiveText)) {
mButtonPositive.setVisibility(View.GONE);
} else {
mButtonPositive.setText(mButtonPositiveText);
mButtonPositive.setVisibility(View.VISIBLE);
whichButtons = whichButtons | BIT_BUTTON_POSITIVE;
}
mButtonNegative = (Button) buttonPanel.findViewById(R.id.button2);
mButtonNegative.setOnClickListener(mButtonHandler);
if (TextUtils.isEmpty(mButtonNegativeText)) {
mButtonNegative.setVisibility(View.GONE);
} else {
mButtonNegative.setText(mButtonNegativeText);
mButtonNegative.setVisibility(View.VISIBLE);
whichButtons = whichButtons | BIT_BUTTON_NEGATIVE;
}
mButtonNeutral = (Button) buttonPanel.findViewById(R.id.button3);
mButtonNeutral.setOnClickListener(mButtonHandler);
if (TextUtils.isEmpty(mButtonNeutralText)) {
mButtonNeutral.setVisibility(View.GONE);
} else {
mButtonNeutral.setText(mButtonNeutralText);
mButtonNeutral.setVisibility(View.VISIBLE);
whichButtons = whichButtons | BIT_BUTTON_NEUTRAL;
}
if (shouldCenterSingleButton(mContext)) {
/*
* If we only have 1 button it should be centered on the layout and
* expand to fill 50% of the available space.
*/
if (whichButtons == BIT_BUTTON_POSITIVE) {
centerButton(mButtonPositive);
} else if (whichButtons == BIT_BUTTON_NEGATIVE) {
centerButton(mButtonNegative);
} else if (whichButtons == BIT_BUTTON_NEUTRAL) {
centerButton(mButtonNeutral);
}
}
final boolean hasButtons = whichButtons != 0;
if (!hasButtons) {
buttonPanel.setVisibility(View.GONE);
}
}
private void centerButton(Button button) {
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) button.getLayoutParams();
params.gravity = Gravity.CENTER_HORIZONTAL;
params.weight = 0.5f;
button.setLayoutParams(params);
View leftSpacer = mWindow.findViewById(R.id.leftSpacer);
if (leftSpacer != null) {
leftSpacer.setVisibility(View.VISIBLE);
}
View rightSpacer = mWindow.findViewById(R.id.rightSpacer);
if (rightSpacer != null) {
rightSpacer.setVisibility(View.VISIBLE);
}
}
private void setBackground(TypedArray a, View topPanel, View contentPanel, View customPanel,
View buttonPanel, boolean hasTitle, boolean hasCustomView, boolean hasButtons) {
int fullDark = 0;
int topDark = 0;
int centerDark = 0;
int bottomDark = 0;
int fullBright = 0;
int topBright = 0;
int centerBright = 0;
int bottomBright = 0;
int bottomMedium = 0;
// If the needsDefaultBackgrounds attribute is set, we know we're
// inheriting from a framework style.
final boolean needsDefaultBackgrounds = a.getBoolean(
R.styleable.AlertDialog_needsDefaultBackgrounds, true);
if (needsDefaultBackgrounds) {
fullDark = R.drawable.popup_full_dark;
topDark = R.drawable.popup_top_dark;
centerDark = R.drawable.popup_center_dark;
bottomDark = R.drawable.popup_bottom_dark;
fullBright = R.drawable.popup_full_bright;
topBright = R.drawable.popup_top_bright;
centerBright = R.drawable.popup_center_bright;
bottomBright = R.drawable.popup_bottom_bright;
bottomMedium = R.drawable.popup_bottom_medium;
}
topBright = a.getResourceId(R.styleable.AlertDialog_topBright, topBright);
topDark = a.getResourceId(R.styleable.AlertDialog_topDark, topDark);
centerBright = a.getResourceId(R.styleable.AlertDialog_centerBright, centerBright);
centerDark = a.getResourceId(R.styleable.AlertDialog_centerDark, centerDark);
/* We now set the background of all of the sections of the alert.
* First collect together each section that is being displayed along
* with whether it is on a light or dark background, then run through
* them setting their backgrounds. This is complicated because we need
* to correctly use the full, top, middle, and bottom graphics depending
* on how many views they are and where they appear.
*/
final View[] views = new View[4];
final boolean[] light = new boolean[4];
View lastView = null;
boolean lastLight = false;
int pos = 0;
if (hasTitle) {
views[pos] = topPanel;
light[pos] = false;
pos++;
}
/* The contentPanel displays either a custom text message or
* a ListView. If it's text we should use the dark background
* for ListView we should use the light background. If neither
* are there the contentPanel will be hidden so set it as null.
*/
views[pos] = contentPanel.getVisibility() == View.GONE ? null : contentPanel;
light[pos] = mListView != null;
pos++;
if (hasCustomView) {
views[pos] = customPanel;
light[pos] = mForceInverseBackground;
pos++;
}
if (hasButtons) {
views[pos] = buttonPanel;
light[pos] = true;
}
boolean setView = false;
for (pos = 0; pos < views.length; pos++) {
final View v = views[pos];
if (v == null) {
continue;
}
if (lastView != null) {
if (!setView) {
lastView.setBackgroundResource(lastLight ? topBright : topDark);
} else {
lastView.setBackgroundResource(lastLight ? centerBright : centerDark);
}
setView = true;
}
lastView = v;
lastLight = light[pos];
}
if (lastView != null) {
if (setView) {
bottomBright = a.getResourceId(R.styleable.AlertDialog_bottomBright, bottomBright);
bottomMedium = a.getResourceId(R.styleable.AlertDialog_bottomMedium, bottomMedium);
bottomDark = a.getResourceId(R.styleable.AlertDialog_bottomDark, bottomDark);
// ListViews will use the Bright background, but buttons use the
// Medium background.
lastView.setBackgroundResource(
lastLight ? (hasButtons ? bottomMedium : bottomBright) : bottomDark);
} else {
fullBright = a.getResourceId(R.styleable.AlertDialog_fullBright, fullBright);
fullDark = a.getResourceId(R.styleable.AlertDialog_fullDark, fullDark);
lastView.setBackgroundResource(lastLight ? fullBright : fullDark);
}
}
final ListView listView = mListView;
if (listView != null && mAdapter != null) {
listView.setAdapter(mAdapter);
final int checkedItem = mCheckedItem;
if (checkedItem > -1) {
listView.setItemChecked(checkedItem, true);
listView.setSelectionFromTop(checkedItem,
a.getDimensionPixelSize(R.styleable.AlertDialog_selectionScrollOffset, 0));
}
}
}
AlertDialog.Builder()构建
用到最多得就是使用 AlertDialog.Builder()创建对话框，Builder是AlertDialog的静态内部类，public static class BuilderBuidler中使用private final AlertController.AlertParams P;AlertParams是AlertController的静态内部类，Builder中设置的参数，其实都是调用AlertParams对应的方法。
public Builder setTitle(CharSequence title) {
P.mTitle = title;
return this;
Builder中一些设置参数的方法：
- setTitle 系列
- setMessage
- setIcon
- setPositiveButton
-setCancelable - setItems
show() create()
/**
* Creates an {@link AlertDialog} with the arguments supplied to this
* builder.
* <p>
* Calling this method does not display the dialog. If no additional
* processing is needed, {@link #show()} may be called instead to both
* create and display the dialog.
*/
public AlertDialog create() {
// Context has already been wrapped with the appropriate theme.
final AlertDialog dialog = new AlertDialog(P.mContext, 0, false);
P.apply(dialog.mAlert);
dialog.setCancelable(P.mCancelable);
if (P.mCancelable) {
dialog.setCanceledOnTouchOutside(true);
}
dialog.setOnCancelListener(P.mOnCancelListener);
dialog.setOnDismissListener(P.mOnDismissListener);
if (P.mOnKeyListener != null) {
dialog.setOnKeyListener(P.mOnKeyListener);
}
return dialog;
}
/**
* Creates an {@link AlertDialog} with the arguments supplied to this
* builder and immediately displays the dialog.
* <p>
* Calling this method is functionally identical to:
* <pre>
* AlertDialog dialog = builder.create();
* dialog.show();
* </pre>
*/
public AlertDialog show() {
final AlertDialog dialog = create();
dialog.show();
return dialog;
}
AlertParams
public static class AlertParams {
public final Context mContext;
public final LayoutInflater mInflater;
public int mIconId = 0;
public Drawable mIcon;
public int mIconAttrId = 0;
public CharSequence mTitle;
public View mCustomTitleView;
public CharSequence mMessage;
public CharSequence mPositiveButtonText;
public DialogInterface.OnClickListener mPositiveButtonListener;
public CharSequence mNegativeButtonText;
public DialogInterface.OnClickListener mNegativeButtonListener;
public CharSequence mNeutralButtonText;
public DialogInterface.OnClickListener mNeutralButtonListener;
public boolean mCancelable;
public DialogInterface.OnCancelListener mOnCancelListener;
public DialogInterface.OnDismissListener mOnDismissListener;
public DialogInterface.OnKeyListener mOnKeyListener;
public CharSequence[] mItems;
public ListAdapter mAdapter;
public DialogInterface.OnClickListener mOnClickListener;
public int mViewLayoutResId;
public View mView;
public int mViewSpacingLeft;
public int mViewSpacingTop;
public int mViewSpacingRight;
public int mViewSpacingBottom;
public boolean mViewSpacingSpecified = false;
public boolean[] mCheckedItems;
public boolean mIsMultiChoice;
public boolean mIsSingleChoice;
public int mCheckedItem = -1;
public DialogInterface.OnMultiChoiceClickListener mOnCheckboxClickListener;
public Cursor mCursor;
public String mLabelColumn;
public String mIsCheckedColumn;
public boolean mForceInverseBackground;
public AdapterView.OnItemSelectedListener mOnItemSelectedListener;
public OnPrepareListViewListener mOnPrepareListViewListener;
public boolean mRecycleOnMeasure = true;
/**
* Interface definition for a callback to be invoked before the ListView
* will be bound to an adapter.
*/
public interface OnPrepareListViewListener {
/**
* Called before the ListView is bound to an adapter.
* @param listView The ListView that will be shown in the dialog.
*/
void onPrepareListView(ListView listView);
}
public AlertParams(Context context) {
mContext = context;
mCancelable = true;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void apply(AlertController dialog) {
if (mCustomTitleView != null) {
dialog.setCustomTitle(mCustomTitleView);
} else {
if (mTitle != null) {
dialog.setTitle(mTitle);
}
if (mIcon != null) {
dialog.setIcon(mIcon);
}
if (mIconId != 0) {
dialog.setIcon(mIconId);
}
if (mIconAttrId != 0) {
dialog.setIcon(dialog.getIconAttributeResId(mIconAttrId));
}
}
if (mMessage != null) {
dialog.setMessage(mMessage);
}
if (mPositiveButtonText != null) {
dialog.setButton(DialogInterface.BUTTON_POSITIVE, mPositiveButtonText,
mPositiveButtonListener, null);
}
if (mNegativeButtonText != null) {
dialog.setButton(DialogInterface.BUTTON_NEGATIVE, mNegativeButtonText,
mNegativeButtonListener, null);
}
if (mNeutralButtonText != null) {
dialog.setButton(DialogInterface.BUTTON_NEUTRAL, mNeutralButtonText,
mNeutralButtonListener, null);
}
if (mForceInverseBackground) {
dialog.setInverseBackgroundForced(true);
}
// For a list, the client can either supply an array of items or an
// adapter or a cursor
if ((mItems != null) || (mCursor != null) || (mAdapter != null)) {
createListView(dialog);
}
if (mView != null) {
if (mViewSpacingSpecified) {
dialog.setView(mView, mViewSpacingLeft, mViewSpacingTop, mViewSpacingRight,
mViewSpacingBottom);
} else {
dialog.setView(mView);
}
} else if (mViewLayoutResId != 0) {
dialog.setView(mViewLayoutResId);
}
/*
dialog.setCancelable(mCancelable);
dialog.setOnCancelListener(mOnCancelListener);
if (mOnKeyListener != null) {
dialog.setOnKeyListener(mOnKeyListener);
}
*/
}
private void createListView(final AlertController dialog) {
final RecycleListView listView =
(RecycleListView) mInflater.inflate(dialog.mListLayout, null);
final ListAdapter adapter;
if (mIsMultiChoice) {
if (mCursor == null) {
adapter = new ArrayAdapter<CharSequence>(
mContext, dialog.mMultiChoiceItemLayout, R.id.text1, mItems) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
if (mCheckedItems != null) {
boolean isItemChecked = mCheckedItems[position];
if (isItemChecked) {
listView.setItemChecked(position, true);
}
}
return view;
}
};
} else {
adapter = new CursorAdapter(mContext, mCursor, false) {
private final int mLabelIndex;
private final int mIsCheckedIndex;
{
final Cursor cursor = getCursor();
mLabelIndex = cursor.getColumnIndexOrThrow(mLabelColumn);
mIsCheckedIndex = cursor.getColumnIndexOrThrow(mIsCheckedColumn);
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
CheckedTextView text = (CheckedTextView) view.findViewById(R.id.text1);
text.setText(cursor.getString(mLabelIndex));
listView.setItemChecked(
cursor.getPosition(),
cursor.getInt(mIsCheckedIndex) == 1);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return mInflater.inflate(dialog.mMultiChoiceItemLayout,
parent, false);
}
};
}
} else {
final int layout;
if (mIsSingleChoice) {
layout = dialog.mSingleChoiceItemLayout;
} else {
layout = dialog.mListItemLayout;
}
if (mCursor != null) {
adapter = new SimpleCursorAdapter(mContext, layout, mCursor,
new String[] { mLabelColumn }, new int[] { R.id.text1 });
} else if (mAdapter != null) {
adapter = mAdapter;
} else {
adapter = new CheckedItemAdapter(mContext, layout, R.id.text1, mItems);
}
}
if (mOnPrepareListViewListener != null) {
mOnPrepareListViewListener.onPrepareListView(listView);
}
/* Don't directly set the adapter on the ListView as we might
* want to add a footer to the ListView later.
*/
dialog.mAdapter = adapter;
dialog.mCheckedItem = mCheckedItem;
if (mOnClickListener != null) {
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
mOnClickListener.onClick(dialog.mDialogInterface, position);
if (!mIsSingleChoice) {
dialog.mDialogInterface.dismiss();
}
}
});
} else if (mOnCheckboxClickListener != null) {
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
if (mCheckedItems != null) {
mCheckedItems[position] = listView.isItemChecked(position);
}
mOnCheckboxClickListener.onClick(
dialog.mDialogInterface, position, listView.isItemChecked(position));
}
});
}
// Attach a given OnItemSelectedListener to the ListView
if (mOnItemSelectedListener != null) {
listView.setOnItemSelectedListener(mOnItemSelectedListener);
}
if (mIsSingleChoice) {
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
} else if (mIsMultiChoice) {
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
}
listView.mRecycleOnMeasure = mRecycleOnMeasure;
dialog.mListView = listView;
}
}
private static class CheckedItemAdapter extends ArrayAdapter<CharSequence> {
public CheckedItemAdapter(Context context, int resource, int textViewResourceId,
CharSequence[] objects) {
super(context, resource, textViewResourceId, objects);
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public long getItemId(int position) {
return position;
}
}
}
apply方法是把参数在设置到AlertController中，在apply方法中调用了createListView，是给对话框设置显示list，根据传入的item，adapter和cursor。最后赋值到AlertController中。
