我正在制作一个阅读应用程序,它有一个全屏活动。
当用户选择文本的一部分时,会出现一个带有copy选项的contextual action bar
。这是默认行为。但是这个actionbar阻止了下面的文本,所以用户不能选择它。
我想显示一个弹出窗口如下。
我试图从false
返回onCreateActionMode
,但当我这样做时,我也无法选择文本。
我想知道是否有一个标准的方法来实现这一点,因为许多阅读应用程序使用这种设计。
最佳答案
我不知道play books是如何做到这一点的,但是你可以创建一个PopupWindow
并根据选择的文本使用Layout.getSelectionPath
和一点数学计算它的位置。基本上,我们要:
计算选定文本的边界
计算PopupWindow
的边界和初始位置
计算两者之间的差
将PopupWindow
偏移到所选文本上方或下方的水平/垂直静止中心
计算选择界限
From the docs
用高光的表示填充指定的路径
在指定的偏移之间。这通常是一个矩形或
可能不连续的矩形集。如果开始和结束是
同样,返回的路径也是空的。
因此,在我们的例子中,指定的偏移是选择的开始和结束,可以使用Selection.getSelectionStart
和Selection.getSelectionEnd
找到。为了方便起见,TextView
为我们提供了TextView.getSelectionStart
、TextView.getSelectionEnd
和TextView.getLayout
。
final Path selDest = new Path();
final RectF selBounds = new RectF();
final Rect outBounds = new Rect();
// Calculate the selection start and end offset
final int selStart = yourTextView.getSelectionStart();
final int selEnd = yourTextView.getSelectionEnd();
final int min = Math.max(0, Math.min(selStart, selEnd));
final int max = Math.max(0, Math.max(selStart, selEnd));
// Calculate the selection outBounds
yourTextView.getLayout().getSelectionPath(min, max, selDest);
selDest.computeBounds(selBounds, true /* this param is ignored */);
selBounds.roundOut(outBounds);
现在我们有了一个
Rect
的选定文本边界,我们可以选择相对于它放置PopupWindow
的位置。在这种情况下,我们将沿选定文本的顶部或底部水平居中,这取决于显示弹出窗口所需的空间。计算初始弹出坐标
接下来我们需要计算弹出内容的边界。为此,我们首先需要调用
PopupWindow.showAtLocation
,但我们充气的View
的界限不会立即可用,因此我建议使用ViewTreeObserver.OnGlobalLayoutListener
来等待它们可用。popupWindow.showAtLocation(yourTextView, Gravity.TOP, 0, 0)
PopupWindow.showAtLocation
需要:a
View
从中检索一个有效的Window
token,它只是唯一地标识要放置弹出窗口的Window
。一个可选的重力,但在我们的例子中它将
Gravity.TOP
可选的X/Y偏移
因为在弹出内容布局之前,我们无法确定x/y偏移量,所以我们将最初将其放置在默认位置。如果您试图在传入的
PopupWindow.showAtLocation
设置好之前调用View
,您将收到一个WindowManager.BadTokenException
,因此您可以考虑使用ViewTreeObserver.OnGlobalLayoutListener
来避免这一情况,但它主要出现在您选择了文本并旋转设备时。 final Rect cframe = new Rect();
final int[] cloc = new int[2];
popupContent.getLocationOnScreen(cloc);
popupContent.getLocalVisibleRect(cbounds);
popupContent.getWindowVisibleDisplayFrame(cframe);
final int scrollY = ((View) yourTextView.getParent()).getScrollY();
final int[] tloc = new int[2];
yourTextView.getLocationInWindow(tloc);
final int startX = cloc[0] + cbounds.centerX();
final int startY = cloc[1] + cbounds.centerY() - (tloc[1] - cframe.top) - scrollY;
View.getLocationOnScreen
将返回弹出内容的x/y坐标。View.getLocalVisibleRect
将返回弹出内容的边界View.getWindowVisibleDisplayFrame
将返回偏移量以适应操作栏(如果存在)View.getScrollY
将返回我们的y
所在的滚动容器的TextView
偏移量(在我的例子中是ScrollView
)View.getLocationInWindow
将返回我们y
的TextView
偏移量,以防操作栏将其向下推一点一旦我们得到了所需的所有信息,我们就可以计算弹出内容的最终起始x/y,然后用这个来计算它们与所选文本之间的差异
Rect
,这样我们就可以PopupWindow.update
到新的位置。计算偏移弹出坐标
// Calculate the top and bottom offset of the popup relative to the selection bounds
final int popupHeight = cbounds.height();
final int textPadding = yourTextView.getPaddingLeft();
final int topOffset = Math.round(selBounds.top - startY);
final int btmOffset = Math.round(selBounds.bottom - (startY - popupHeight));
// Calculate the x/y coordinates for the popup relative to the selection bounds
final int x = Math.round(selBounds.centerX() + textPadding - startX);
final int y = Math.round(selBounds.top - scrollY < startY ? btmOffset : topOffset);
如果有足够的空间在所选文本上方显示弹出窗口,我们会将其放在那里;否则,我们会将其偏移到所选文本下方。在我的例子中,我的
16dp
周围有TextView
填充,所以这也需要考虑。我们将以最后的x
和y
位置结束,用它来抵消PopupWindow
。 popupWindow.update(x, y, -1, -1);
-1
这里只表示我们为PopupWindow
提供的默认宽度/高度,在我们的情况下,它将ViewGroup.LayoutParams.WRAP_CONTENT
监听选择更改
我们希望每次更改选定文本时都更新
PopupWindow
。监听选择更改的一个简单方法是对
TextView
进行子类划分,并提供对TextView.onSelectionChanged
的回调。public class NotifyingSelectionTextView extends AppCompatTextView {
private SelectionChangeListener listener;
public NotifyingSelectionTextView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onSelectionChanged(int selStart, int selEnd) {
super.onSelectionChanged(selStart, selEnd);
if (listener != null) {
if (hasSelection()) {
listener.onTextSelected();
} else {
listener.onTextUnselected();
}
}
}
public void setSelectionChangeListener(SelectionChangeListener listener) {
this.listener = listener;
}
public interface SelectionChangeListener {
void onTextSelected();
void onTextUnselected();
}
}
监听滚动变化
如果您在类似于
TextView
的滚动容器中有一个ScrollView
,您可能还需要监听滚动更改,以便在滚动时锚定弹出窗口。监听这些消息的一个简单方法是对ScrollView
进行子类划分,并提供对View.onScrollChanged
的回调。public class NotifyingScrollView extends ScrollView {
private ScrollChangeListener listener;
public NotifyingScrollView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (listener != null) {
listener.onScrollChanged();
}
}
public void setScrollChangeListener(ScrollChangeListener listener) {
this.listener = listener;
}
public interface ScrollChangeListener {
void onScrollChanged();
}
}
创建空
ActionMode.Callback
正如您在文章中提到的,我们需要在
true
中返回ActionMode.Callback.onCreateActionMode
,以便我们的文本保持可选。但我们还需要在Menu.clear
中调用ActionMode.Callback.onPrepareActionMode
,以便删除您在ActionMode
中为选定文本找到的所有项。/** An {@link ActionMode.Callback} used to remove all action items from text selection */
static final class EmptyActionMode extends SimpleActionModeCallback {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// Return true to ensure the text is still selectable
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
// Remove all action items to provide an actionmode-less selection
menu.clear();
return true;
}
}
现在我们可以使用
TextView.setCustomSelectionActionModeCallback
来应用我们的自定义ActionMode
。SimpleActionModeCallback
是一个自定义类,它只为ActionMode.Callback
提供存根,类似于ViewPager.SimpleOnPageChangeListener
public class SimpleActionModeCallback implements ActionMode.Callback {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
return false;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
return false;
}
@Override
public void onDestroyActionMode(ActionMode mode) {
}
}
布局
这是我们使用的
Activity
布局:<your.package.name.NotifyingScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/notifying_scroll_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<your.package.name.NotifyingSelectionTextView
android:id="@+id/notifying_text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:textIsSelectable="true"
android:textSize="20sp" />
</your.package.name.NotifyingScrollView>
这是我们的弹出式布局:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/action_mode_popup_bg"
android:orientation="vertical"
tools:ignore="ContentDescription">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageButton
android:id="@+id/view_action_mode_popup_add_note"
style="@style/ActionModePopupButton"
android:src="@drawable/ic_note_add_black_24dp" />
<ImageButton
android:id="@+id/view_action_mode_popup_translate"
style="@style/ActionModePopupButton"
android:src="@drawable/ic_translate_black_24dp" />
<ImageButton
android:id="@+id/view_action_mode_popup_search"
style="@style/ActionModePopupButton"
android:src="@drawable/ic_search_black_24dp" />
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_margin="8dp"
android:background="@android:color/darker_gray" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageButton
android:id="@+id/view_action_mode_popup_red"
style="@style/ActionModePopupSwatch"
android:src="@drawable/round_red" />
<ImageButton
android:id="@+id/view_action_mode_popup_yellow"
style="@style/ActionModePopupSwatch"
android:src="@drawable/round_yellow" />
<ImageButton
android:id="@+id/view_action_mode_popup_green"
style="@style/ActionModePopupSwatch"
android:src="@drawable/round_green" />
<ImageButton
android:id="@+id/view_action_mode_popup_blue"
style="@style/ActionModePopupSwatch"
android:src="@drawable/round_blue" />
<ImageButton
android:id="@+id/view_action_mode_popup_clear_format"
style="@style/ActionModePopupSwatch"
android:src="@drawable/ic_format_clear_black_24dp"
android:visibility="gone" />
</LinearLayout>
</LinearLayout>
以下是我们的弹出式按钮样式:
<style name="ActionModePopupButton">
<item name="android:layout_width">48dp</item>
<item name="android:layout_height">48dp</item>
<item name="android:layout_weight">1</item>
<item name="android:background">?selectableItemBackground</item>
</style>
<style name="ActionModePopupSwatch" parent="ActionModePopupButton">
<item name="android:padding">12dp</item>
</style>
乌蒂尔
您将看到的
ViewUtils.onGlobalLayout
只是一个处理一些ViewTreeObserver.OnGlobalLayoutListener
样板文件的实用方法。public static void onGlobalLayout(final View view, final Runnable runnable) {
final OnGlobalLayoutListener listener = new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
runnable.run();
}
};
view.getViewTreeObserver().addOnGlobalLayoutListener(listener);
}
一起带来
所以,现在我们已经:
计算选定的文本边界
计算弹出边界
计算差异并确定弹出窗口偏移
提供了一种监听滚动更改和选择更改的方法
创建了我们的
Activity
和弹出式布局把所有的东西放在一起可能看起来像:
public class ActionModePopupActivity extends AppCompatActivity
implements ScrollChangeListener, SelectionChangeListener {
private static final int DEFAULT_WIDTH = -1;
private static final int DEFAULT_HEIGHT = -1;
private final Point currLoc = new Point();
private final Point startLoc = new Point();
private final Rect cbounds = new Rect();
private final PopupWindow popupWindow = new PopupWindow();
private final ActionMode.Callback emptyActionMode = new EmptyActionMode();
private NotifyingSelectionTextView yourTextView;
@SuppressLint("InflateParams")
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_action_mode_popup);
// Initialize the popup content, only add it to the Window once we've selected text
final LayoutInflater inflater = LayoutInflater.from(this);
popupWindow.setContentView(inflater.inflate(R.layout.view_action_mode_popup, null));
popupWindow.setWidth(WRAP_CONTENT);
popupWindow.setHeight(WRAP_CONTENT);
// Initialize to the NotifyingScrollView to observe scroll changes
final NotifyingScrollView scroll
= (NotifyingScrollView) findViewById(R.id.notifying_scroll_view);
scroll.setScrollChangeListener(this);
// Initialize the TextView to observe selection changes and provide an empty ActionMode
yourTextView = (NotifyingSelectionTextView) findViewById(R.id.notifying_text_view);
yourTextView.setText(IPSUM);
yourTextView.setSelectionChangeListener(this);
yourTextView.setCustomSelectionActionModeCallback(emptyActionMode);
}
@Override
public void onScrollChanged() {
// Anchor the popup while the user scrolls
if (popupWindow.isShowing()) {
final Point ploc = calculatePopupLocation();
popupWindow.update(ploc.x, ploc.y, DEFAULT_WIDTH, DEFAULT_HEIGHT);
}
}
@Override
public void onTextSelected() {
final View popupContent = popupWindow.getContentView();
if (popupWindow.isShowing()) {
// Calculate the updated x/y pop coordinates
final Point ploc = calculatePopupLocation();
popupWindow.update(ploc.x, ploc.y, DEFAULT_WIDTH, DEFAULT_HEIGHT);
} else {
// Add the popup to the Window and position it relative to the selected text bounds
ViewUtils.onGlobalLayout(yourTextView, () -> {
popupWindow.showAtLocation(yourTextView, TOP, 0, 0);
// Wait for the popup content to be laid out
ViewUtils.onGlobalLayout(popupContent, () -> {
final Rect cframe = new Rect();
final int[] cloc = new int[2];
popupContent.getLocationOnScreen(cloc);
popupContent.getLocalVisibleRect(cbounds);
popupContent.getWindowVisibleDisplayFrame(cframe);
final int scrollY = ((View) yourTextView.getParent()).getScrollY();
final int[] tloc = new int[2];
yourTextView.getLocationInWindow(tloc);
final int startX = cloc[0] + cbounds.centerX();
final int startY = cloc[1] + cbounds.centerY() - (tloc[1] - cframe.top) - scrollY;
startLoc.set(startX, startY);
final Point ploc = calculatePopupLocation();
popupWindow.update(ploc.x, ploc.y, DEFAULT_WIDTH, DEFAULT_HEIGHT);
});
});
}
}
@Override
public void onTextUnselected() {
popupWindow.dismiss();
}
/** Used to calculate where we should position the {@link PopupWindow} */
private Point calculatePopupLocation() {
final ScrollView parent = (ScrollView) yourTextView.getParent();
// Calculate the selection start and end offset
final int selStart = yourTextView.getSelectionStart();
final int selEnd = yourTextView.getSelectionEnd();
final int min = Math.max(0, Math.min(selStart, selEnd));
final int max = Math.max(0, Math.max(selStart, selEnd));
// Calculate the selection bounds
final RectF selBounds = new RectF();
final Path selection = new Path();
yourTextView.getLayout().getSelectionPath(min, max, selection);
selection.computeBounds(selBounds, true /* this param is ignored */);
// Retrieve the center x/y of the popup content
final int cx = startLoc.x;
final int cy = startLoc.y;
// Calculate the top and bottom offset of the popup relative to the selection bounds
final int popupHeight = cbounds.height();
final int textPadding = yourTextView.getPaddingLeft();
final int topOffset = Math.round(selBounds.top - cy);
final int btmOffset = Math.round(selBounds.bottom - (cy - popupHeight));
// Calculate the x/y coordinates for the popup relative to the selection bounds
final int scrollY = parent.getScrollY();
final int x = Math.round(selBounds.centerX() + textPadding - cx);
final int y = Math.round(selBounds.top - scrollY < cy ? btmOffset : topOffset);
currLoc.set(x, y - scrollY);
return currLoc;
}
/** An {@link ActionMode.Callback} used to remove all action items from text selection */
static final class EmptyActionMode extends SimpleActionModeCallback {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// Return true to ensure the yourTextView is still selectable
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
// Remove all action items to provide an actionmode-less selection
menu.clear();
return true;
}
}
}
结果
With the action bar (link to video)
Without the action bar (link to video)
奖励-动画
因为我们知道
PopupWindow
的起始位置和偏移位置随着选择的变化而变化,所以当我们移动对象时,可以很容易地在两个值之间执行线性插值来创建一个良好的动画。public static float lerp(float a, float b, float v) {
return a + (b - a) * v;
}
private static final int DEFAULT_ANIM_DUR = 350;
private static final int DEFAULT_ANIM_DELAY = 500;
@Override
public void onTextSelected() {
final View popupContent = popupWindow.getContentView();
if (popupWindow.isShowing()) {
// Calculate the updated x/y pop coordinates
popupContent.getHandler().removeCallbacksAndMessages(null);
popupContent.postDelayed(() -> {
// The current x/y location of the popup
final int currx = currLoc.x;
final int curry = currLoc.y;
// Calculate the updated x/y pop coordinates
final Point ploc = calculatePopupLocation();
currLoc.set(ploc.x, ploc.y);
// Linear interpolate between the current and updated popup coordinates
final ValueAnimator anim = ValueAnimator.ofFloat(0f, 1f);
anim.addUpdateListener(animation -> {
final float v = (float) animation.getAnimatedValue();
final int x = Math.round(AnimUtils.lerp(currx, ploc.x, v));
final int y = Math.round(AnimUtils.lerp(curry, ploc.y, v));
popupWindow.update(x, y, DEFAULT_WIDTH, DEFAULT_HEIGHT);
});
anim.setDuration(DEFAULT_ANIM_DUR);
anim.start();
}, DEFAULT_ANIM_DELAY);
} else {
...
}
}
结果
With the action bar - animation (link to video)
额外的
我不讨论如何将单击侦听器附加到弹出操作,可能有几种方法可以通过不同的计算和实现来实现相同的效果。但我要说的是,如果你想检索选定的文本,然后对其进行处理,you'd just need to
CharSequence.subSequence
the min
and max
from the selected text。不管怎样,我希望这对你有帮助!如果你有任何问题,请告诉我。
关于android - 选择textview时如何显示弹出窗口而不是CAB?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43689020/