feat: 优化代码

app/src/main/java/io/legado/app/ui/widget/ScrollTextView.java

@@ -1,103 +0,0 @@
-package io.legado.app.ui.widget;
-
-import android.annotation.SuppressLint;
-import android.content.Context;
-import android.text.Layout;
-import android.util.AttributeSet;
-import android.view.MotionEvent;
-
-import androidx.appcompat.widget.AppCompatTextView;
-
-public class ScrollTextView extends AppCompatTextView {
-
-    //滑动距离的最大边界
-    private int mOffsetHeight;
-
-    //是否到顶或者到底的标志
-    private boolean mBottomFlag = false;
-
-
-    public ScrollTextView(Context context) {
-        super(context);
-    }
-
-    public ScrollTextView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    public ScrollTextView(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-    }
-
-    @Override
-    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
-        initOffsetHeight();
-    }
-
-    @Override
-    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
-        super.onTextChanged(text, start, lengthBefore, lengthAfter);
-        initOffsetHeight();
-    }
-
-    private void initOffsetHeight() {
-        int paddingTop;
-        int paddingBottom;
-        int mHeight;
-        int mLayoutHeight;
-
-        //获得内容面板
-        Layout mLayout = getLayout();
-        if (mLayout == null) return;
-        //获得内容面板的高度
-        mLayoutHeight = mLayout.getHeight();
-        //获取上内边距
-        paddingTop = getTotalPaddingTop();
-        //获取下内边距
-        paddingBottom = getTotalPaddingBottom();
-
-        //获得控件的实际高度
-        mHeight = getMeasuredHeight();
-
-        //计算滑动距离的边界
-        mOffsetHeight = mLayoutHeight + paddingTop + paddingBottom - mHeight;
-        if (mOffsetHeight <= 0) {
-            scrollTo(0, 0);
-        }
-    }
-
-    @Override
-    public boolean dispatchTouchEvent(MotionEvent event) {
-        if (event.getAction() == MotionEvent.ACTION_DOWN) {
-            //如果是新的按下事件，则对mBottomFlag重新初始化
-            mBottomFlag = mOffsetHeight <= 0;
-        }
-        //如果已经不要这次事件，则传出取消的信号，这里的作用不大
-        if (mBottomFlag) {
-            event.setAction(MotionEvent.ACTION_CANCEL);
-        }
-        return super.dispatchTouchEvent(event);
-    }
-
-    @SuppressLint("ClickableViewAccessibility")
-    @Override
-    public boolean onTouchEvent(MotionEvent event) {
-        boolean result = super.onTouchEvent(event);
-        //如果是需要拦截，则再拦截，这个方法会在onScrollChanged方法之后再调用一次
-        if (!mBottomFlag)
-            getParent().requestDisallowInterceptTouchEvent(true);
-        return result;
-    }
-
-    @Override
-    protected void onScrollChanged(int horiz, int vert, int oldHoriz, int oldVert) {
-        super.onScrollChanged(horiz, vert, oldHoriz, oldVert);
-        if (vert == mOffsetHeight || vert == 0) {
-            //这里触发父布局或祖父布局的滑动事件
-            getParent().requestDisallowInterceptTouchEvent(false);
-            mBottomFlag = true;
-        }
-    }
-
-}

app/src/main/java/io/legado/app/ui/widget/ScrollTextView.kt

@@ -0,0 +1,81 @@
+package io.legado.app.ui.widget
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+import androidx.appcompat.widget.AppCompatTextView
+
+class ScrollTextView(context: Context?, attrs: AttributeSet?) : AppCompatTextView(context, attrs) {
+    //滑动距离的最大边界
+    private var mOffsetHeight = 0
+
+    //是否到顶或者到底的标志
+    private var mBottomFlag = false
+
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
+        initOffsetHeight()
+    }
+
+    override fun onTextChanged(
+        text: CharSequence,
+        start: Int,
+        lengthBefore: Int,
+        lengthAfter: Int
+    ) {
+        super.onTextChanged(text, start, lengthBefore, lengthAfter)
+        initOffsetHeight()
+    }
+
+    private fun initOffsetHeight() {
+        val mLayoutHeight: Int
+
+        //获得内容面板
+        val mLayout = layout ?: return
+        //获得内容面板的高度
+        mLayoutHeight = mLayout.height
+        //获取上内边距
+        val paddingTop: Int = totalPaddingTop
+        //获取下内边距
+        val paddingBottom: Int = totalPaddingBottom
+
+        //获得控件的实际高度
+        val mHeight: Int = measuredHeight
+
+        //计算滑动距离的边界
+        mOffsetHeight = mLayoutHeight + paddingTop + paddingBottom - mHeight
+        if (mOffsetHeight <= 0) {
+            scrollTo(0, 0)
+        }
+    }
+
+    override fun dispatchTouchEvent(event: MotionEvent): Boolean {
+        if (event.action == MotionEvent.ACTION_DOWN) {
+            //如果是新的按下事件，则对mBottomFlag重新初始化
+            mBottomFlag = mOffsetHeight <= 0
+        }
+        //如果已经不要这次事件，则传出取消的信号，这里的作用不大
+        if (mBottomFlag) {
+            event.action = MotionEvent.ACTION_CANCEL
+        }
+        return super.dispatchTouchEvent(event)
+    }
+
+    @SuppressLint("ClickableViewAccessibility")
+    override fun onTouchEvent(event: MotionEvent): Boolean {
+        val result = super.onTouchEvent(event)
+        //如果是需要拦截，则再拦截，这个方法会在onScrollChanged方法之后再调用一次
+        if (!mBottomFlag) parent.requestDisallowInterceptTouchEvent(true)
+        return result
+    }
+
+    override fun onScrollChanged(horiz: Int, vert: Int, oldHoriz: Int, oldVert: Int) {
+        super.onScrollChanged(horiz, vert, oldHoriz, oldVert)
+        if (vert == mOffsetHeight || vert == 0) {
+            //这里触发父布局或祖父布局的滑动事件
+            parent.requestDisallowInterceptTouchEvent(false)
+            mBottomFlag = true
+        }
+    }
+}