android – 如何在选择textview时显示弹出窗口而不是CAB？
作者：互联网
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,会出现一个带有复制选项的上下文操作栏.这是默认行为.但是此操作栏会阻止其下的文本,因此用户无法选择它.
我想显示一个如下所示的弹出窗口.
我尝试从onCreateActionMode返回false,但是当我这样做时,我也无法选择文本.
我想知道是否有一种标准的方法来实现这一点,因为许多阅读应用程序都使用这种设计.
解决方法:
我不知道Play Books是如何实现这一点的,但你可以创建一个PopupWindow,并根据所选文本使用Layout.getSelectionPath和一点点数学来计算它的位置.基本上,我们将：
>计算所选文本的边界
>计算PopupWindow的边界和初始位置
>计算两者之间的差异
>将PopupWindow偏移到水平/垂直居中于所选文本的上方或下方
计算选择范围
Fills in the specified Path with a representation of a highlight
between the specified offsets. This will often be a rectangle or a
potentially discontinuous set of rectangles. If the start and end are
the same, the returned path is empty.
因此,在我们的情况下,指定的偏移量将是选择的开始和结束,可以使用Selection.getSelectionStart和Selection.getSelectionEnd找到.为方便起见,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);
现在我们有了所选文本边界的Rect,我们可以选择我们想要将PopupWindow放在哪里.在这种情况下,我们将沿着所选文本的顶部或底部水平居中,具体取决于我们显示弹出窗口的空间大小.
计算初始弹出坐标
接下来,我们需要计算弹出内容的范围.要做到这一点,我们首先需要调用PopupWindow.showAtLocation,但是我们膨胀的View的界限不会立即可用,因此我建议使用ViewTreeObserver.OnGlobalLayoutListener等待它们可用.
popupWindow.showAtLocation(yourTextView, Gravity.TOP, 0, 0)
PopupWindow.showAtLocation需要：
>一个用于检索有效Window token的视图,它只是唯一标识要放置弹出窗口的窗口
>可选的重力,但在我们的例子中它将是Gravity.TOP
>可选的x / y偏移量
由于我们无法确定弹出内容布局之前的x / y偏移量,因此我们最初将它放在默认位置.如果你尝试在传入的View之前调用PopupWindow.showAtLocation,你会收到一个WindowManager.BadTokenException,所以你可以考虑使用ViewTreeObserver.OnGlobalLayoutListener来避免这种情况,但是当你选择了文本时它会出现.旋转你的设备.
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将返回弹出内容的界限
> View.getWindowVisibleDisplayFrame将返回偏移以适应操作栏(如果存在)
> View.getScrollY将返回我们TextView所在的任何滚动容器的y偏移量(在我的情况下为ScrollView)
> View.getLocationInWindow将返回我们TextView的y偏移量,以防操作栏将其向下推一点
一旦我们获得了所需的所有信息,我们就可以计算出弹出内容的最终起始x / y,然后使用它来计算它们与所选文本Rect之间的差异,这样我们就可以PopupWindow.update到新位置.
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,我们会把它放在那里;否则,我们会将其偏移到所选文本下方.在我的情况下,我在TextView周围有16dp填充,因此也需要考虑.我们最终将得到最终的x和y位置以抵消PopupWindow.
popupWindow.update(x, y, -1, -1);
-1这里只代表我们为PopupWindow提供的默认宽度/高度,在我们的例子中它将是ViewGroup.LayoutParams.WRAP_CONTENT
倾听选择的变化
我们希望PopupWindow每次更改所选文本时都会更新.
监听选择更改的一种简单方法是将TextView子类化并提供对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();
}
}
听滚动更改
如果在ScrollView等滚动容器中有TextView,您可能还希望监听滚动更改,以便在滚动时锚定弹出窗口.一种简单的方法是监听ScrollView,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();
}
}
创建一个空的ActionMode.Callback
就像你在帖子中提到的那样,我们需要在ActionMode.Callback.onCreateActionMode中返回true,以便我们的文本保持可选.但是我们还需要在ActionMode.Callback.onPrepareActionMode中调用Menu.clear,以便删除在ActionMode中为所选文本找到的所有项目.
/** 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,只为ActionMode.Callback提供存根,有点类似于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
这是我们正在使用的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>
这些是我们的弹出按钮样式：
<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>
UTIL
您将看到的ViewUtils.onGlobalLayout只是一个用于处理某些ViewTreeObserver.OnGlobalLayoutListener样板的util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);
}
完全带来它
那么,现在我们已经：
>计算选定的文本范围
>计算弹出范围
>计算差异并确定弹出偏移量
>提供了一种监听滚动更改和选择更改的方法
>创建了我们的活动和弹出布局
把所有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)：
奖金 – 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,所以我们可以轻松地在两个值之间执行线性插值,以便在我们移动物体时创建一个漂亮的动画.
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
我没有讨论如何将单击侦听器附加到弹出操作上,并且可能有多种方法可以通过不同的计算和实现来实现相同的效果.但我要提一下,如果你想检索所选文本,然后用它做一些事情,you’d just need to CharSequence.subSequence the min and max from the selected text.
无论如何,我希望这对你有所帮助！如果您有任何疑问,请告诉我.
标签：android-actionmode,android,textview,android-popupwindow 来源： https://codeday.me/bug/20190724/1523162.html