version:

fix: update:增加资讯列表
2023-01-03 09:15:22 +08:00
parent 4b01f9987f
commit 39d0f0b597
8 changed files with 530 additions and 10 deletions
--- a/app/src/main/java/com/uiuios/aios/view/ExpandTextView.java
+++ b/app/src/main/java/com/uiuios/aios/view/ExpandTextView.java
@@ -0,0 +1,135 @@
+package com.uiuios.aios.view;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.text.Layout;
+import android.text.StaticLayout;
+import android.util.AttributeSet;
+
+import androidx.annotation.Nullable;
+import androidx.appcompat.widget.AppCompatTextView;
+
+public class ExpandTextView extends AppCompatTextView {
+    /**
+     * true：展开，false：收起
+     */
+    boolean mExpanded;
+    /**
+     * 状态回调
+     */
+    Callback mCallback;
+    /**
+     * 源文字内容
+     */
+    String mText = "";
+    /**
+     * 最多展示的行数
+     */
+    final int maxLineCount = 3;
+    /**
+     * 省略文字
+     */
+    final String ellipsizeText = "...";
+
+    public ExpandTextView(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        // 文字计算辅助工具
+        StaticLayout sl = new StaticLayout(mText, getPaint(), getMeasuredWidth() - getPaddingLeft() - getPaddingRight()
+                , Layout.Alignment.ALIGN_CENTER, 1, 0, true);
+        // 总计行数
+        int lineCount = sl.getLineCount();
+        if (lineCount > maxLineCount) {
+            if (mExpanded) {
+                setText(mText);
+                mCallback.onExpand();
+            } else {
+                lineCount = maxLineCount;
+
+                // 省略文字的宽度
+                float dotWidth = getPaint().measureText(ellipsizeText);
+
+                // 找出第 showLineCount 行的文字
+                int start = sl.getLineStart(lineCount - 1);
+                int end = sl.getLineEnd(lineCount - 1);
+                String lineText = mText.substring(start, end);
+
+                // 将第 showLineCount 行最后的文字替换为 ellipsizeText
+                int endIndex = 0;
+                for (int i = lineText.length() - 1; i >= 0; i--) {
+                    String str = lineText.substring(i, lineText.length());
+                    // 找出文字宽度大于 ellipsizeText 的字符
+                    if (getPaint().measureText(str) >= dotWidth) {
+                        endIndex = i;
+                        break;
+                    }
+                }
+
+                // 新的第 showLineCount 的文字
+                String newEndLineText = lineText.substring(0, endIndex) + ellipsizeText;
+                // 最终显示的文字
+                setText(mText.substring(0, start) + newEndLineText);
+
+                mCallback.onCollapse();
+            }
+        } else {
+            setText(mText);
+            mCallback.onLoss();
+        }
+
+        // 重新计算高度
+        int lineHeight = 0;
+        for (int i = 0; i < lineCount; i++) {
+            Rect lineBound = new Rect();
+            sl.getLineBounds(i, lineBound);
+            lineHeight += lineBound.height();
+        }
+        lineHeight += getPaddingTop() + getPaddingBottom();
+        setMeasuredDimension(getMeasuredWidth(), lineHeight);
+    }
+
+    /**
+     * 设置要显示的文字以及状态
+     * @param text
+     * @param expanded true：展开，false：收起
+     * @param callback
+     */
+    public void setText(String text, boolean expanded, Callback callback) {
+        mText = text;
+        mExpanded = expanded;
+        mCallback = callback;
+
+        // 设置要显示的文字，这一行必须要，否则 onMeasure 宽度测量不正确
+        setText(text);
+    }
+
+    /**
+     * 展开收起状态变化
+     * @param expanded
+     */
+    public void setChanged(boolean expanded) {
+        mExpanded = expanded;
+        requestLayout();
+    }
+
+    public interface Callback {
+        /**
+         * 展开状态
+         */
+        void onExpand();
+
+        /**
+         * 收起状态
+         */
+        void onCollapse();
+
+        /**
+         * 行数小于最小行数，不满足展开或者收起条件
+         */
+        void onLoss();
+    }
+}