如何将浮动动作按钮带到Android应用程序之外

Question

我想创建一个android应用程序，可以翻译用户屏幕上的任何文本。它应该在所有应用程序的整个安卓手机上工作。我想在应用程序外部添加一个浮动操作按钮，使其作为可见、可移动和可点击的后台服务运行。浮动按钮将采取复制的文本，然后使用谷歌翻译API翻译。

请帮帮我，我需要一些指导和资源。

Answer 1

请检查以下Java和XML文件中的浮动操作按钮

JAVA

package com.example;
import android.content.Context;
import android.support.design.widget.FloatingActionButton;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
public class MovableFloatingActionButton extends FloatingActionButton implements View.OnTouchListener {
private final static float CLICK_DRAG_TOLERANCE = 10; // Often, there will be a slight, unintentional, drag when the user taps the FAB, so we need to account for this.
private float downRawX, downRawY;
private float dX, dY;
public MovableFloatingActionButton(Context context) {
super(context);
init();
}
public MovableFloatingActionButton(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MovableFloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
setOnTouchListener(this);
}
@Override
public boolean onTouch(View view, MotionEvent motionEvent){
ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams)view.getLayoutParams();
int action = motionEvent.getAction();
if (action == MotionEvent.ACTION_DOWN) {
downRawX = motionEvent.getRawX();
downRawY = motionEvent.getRawY();
dX = view.getX() - downRawX;
dY = view.getY() - downRawY;
return true; // Consumed
}
else if (action == MotionEvent.ACTION_MOVE) {
int viewWidth = view.getWidth();
int viewHeight = view.getHeight();
View viewParent = (View)view.getParent();
int parentWidth = viewParent.getWidth();
int parentHeight = viewParent.getHeight();
float newX = motionEvent.getRawX() + dX;
newX = Math.max(layoutParams.leftMargin, newX); // Don't allow the FAB past the left hand side of the parent
newX = Math.min(parentWidth - viewWidth - layoutParams.rightMargin, newX); // Don't allow the FAB past the right hand side of the parent
float newY = motionEvent.getRawY() + dY;
newY = Math.max(layoutParams.topMargin, newY); // Don't allow the FAB past the top of the parent
newY = Math.min(parentHeight - viewHeight - layoutParams.bottomMargin, newY); // Don't allow the FAB past the bottom of the parent
view.animate()
.x(newX)
.y(newY)
.setDuration(0)
.start();
return true; // Consumed
}
else if (action == MotionEvent.ACTION_UP) {
float upRawX = motionEvent.getRawX();
float upRawY = motionEvent.getRawY();
float upDX = upRawX - downRawX;
float upDY = upRawY - downRawY;
if (Math.abs(upDX) < CLICK_DRAG_TOLERANCE && Math.abs(upDY) < CLICK_DRAG_TOLERANCE) { // A click
return performClick();
}
else { // A drag
return true; // Consumed
}
}
else {
return super.onTouchEvent(motionEvent);
}
}
}

XML

<com.example.MovableFloatingActionButton
android:id="@+id/btnFab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
android:src="@drawable/ic_navigate_next_white_24dp"/>