针对Android Tv的自定义RecyclerView
2248831048
8年前
<p>前言：Android TV Launcher页在RecyclerView出来之前大家用GridView去实现。TV开发有五向键的监听，遥控器hover监听，点击事件等。用GridView去处理焦点是有一定挑战性的，往往会出现不可预料焦点错乱问题。这里封装了一个针对TV的RecyclerView，很方便的处理了这些事件。</p> <p>下面是效果图：</p> <p><img src="https://simg.open-open.com/show/e5c6499187646c73d70836c4b1bea1d0.gif"></p> <p>封装了RecyclerView实现了一下一些功能:</p> <p>1.响应五向键，按下五向键的上下左右会跟着移动，并获得焦点，在获得焦点时会抬高</p> <p>2.在鼠标hover在条目上时会获得焦点。</p> <p>3.添加了条目的点击和长按事件。</p> <p>4.添加了是否第一个可见条目和是否是最后一个可见条目的方法。</p> <p>5.在item获得焦点时和失去焦点时，这里有相应的回调方法。</p> <p>下面分析一下一些关键的点：</p> <p>1.鼠标滑动时避免跟着滑动，只响应五向键和左右箭头</p> <pre> <code class="language-java">@Override public boolean dispatchTouchEvent(MotionEvent ev) { //在recyclerView的move事件情况下，拦截调，只让它响应五向键和左右箭头移动 LogUtil.i(this, "CustomRecycleView.dispatchTouchEvent."); return ev.getAction() == MotionEvent.ACTION_MOVE || super.dispatchTouchEvent(ev); }</code></pre> <p>2.使用StaggeredGridLayoutManager实现管理，如果使用GridLayoutManager会出现焦点的错乱，当使用五向键左右移动时，会从上面转移到下面。原因是GridLayoutManager会存在分组。</p> <pre> <code class="language-java">//设置布局管理器 StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.HORIZONTAL); mRecyclerView.setLayoutManager(layoutManager);</code></pre> <p>3.设置RecyclerView的item有焦点。按五向键，焦点会跟着一起移动</p> <pre> <code class="language-java">holder.itemView.setFocusable(true);</code></pre> <p>4，左右键，让RecyclerView跟着一起滚动，并获得焦点：</p> <pre> <code class="language-java">@Override public boolean dispatchKeyEvent(KeyEvent event) { boolean result = super.dispatchKeyEvent(event); int dx = this.getChildAt(0).getWidth(); View focusView = this.getFocusedChild(); if (focusView != null) { switch (event.getKeyCode()) { case KeyEvent.KEYCODE_DPAD_RIGHT: if (event.getAction() == KeyEvent.ACTION_UP) { return true; } else { View rightView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_RIGHT); LogUtil.i(this, "rightView is null:" + (rightView == null)); if (rightView != null) { rightView.requestFocusFromTouch(); return true; } else { this.smoothScrollBy(dx, 0); return true; } } case KeyEvent.KEYCODE_DPAD_LEFT: View leftView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_LEFT); LogUtil.i(this, "left is null:" + (leftView == null)); if (event.getAction() == KeyEvent.ACTION_UP) { return true; } else { if (leftView != null) { leftView.requestFocusFromTouch(); return true; } else { this.smoothScrollBy(-dx, 0); return true; } } } } return result; }</code></pre> <p>这里请求获取焦点的方法是：</p> <pre> <code class="language-java">rightView.requestFocusFromTouch();</code></pre> <p>TV的焦点的处理的逻辑比较复杂：</p> <p>可以参考这篇文章： <a href="/misc/goto?guid=4959728742025965967" rel="nofollow,noindex">http://www.cnblogs.com/myzh/p/3664544.html</a></p> <p>5.在holder里监听到焦点变化时做一些处理：</p> <pre> <code class="language-java">holder.itemView.setOnFocusChangeListener(new View.OnFocusChangeListener() { @Override public void onFocusChange(View v, boolean hasFocus) { if (hasFocus) { focusStatus(v); } else { normalStatus(v); } } }); /** * item获得焦点时调用 * * @param itemView view */ private void focusStatus(View itemView) { if (itemView == null) { return; } if (Build.VERSION.SDK_INT >= 21) { //抬高Z轴 ViewCompat.animate(itemView).scaleX(1.10f).scaleY(1.10f).translationZ(1).start(); } else { ViewCompat.animate(itemView).scaleX(1.10f).scaleY(1.10f).start(); ViewGroup parent = (ViewGroup) itemView.getParent(); parent.requestLayout(); parent.invalidate(); } onItemFocus(itemView); } /** * 当item获得焦点时处理 * * @param itemView itemView */ protected abstract void onItemFocus(View itemView); /** * item失去焦点时 * * @param itemView item对应的View */ private void normalStatus(View itemView) { if (itemView == null) { return; } if (Build.VERSION.SDK_INT >= 21) { ViewCompat.animate(itemView).scaleX(1.0f).scaleY(1.0f).translationZ(0).start(); } else { ViewCompat.animate(itemView).scaleX(1.0f).scaleY(1.0f).start(); ViewGroup parent = (ViewGroup) itemView.getParent(); parent.requestLayout(); parent.invalidate(); } onItemGetNormal(itemView); } /** * 当条目失去焦点时调用 * * @param itemView 条目对应的View */ protected abstract void onItemGetNormal(View itemView);</code></pre> <p>这里抽象了两个方法，当item获得焦点和失去焦点时调用。获得焦点时条目会抬高，这里是抬高了Z轴。</p> <p>6.获取在第一个和最后一个可见的条目，根据这些状态去显示和隐藏左右箭头。</p> <pre> <code class="language-java">/** * 第一个条目是否可见 * * @return 可见返回true，不可见返回false */ public boolean isFirstItemVisible() { LayoutManager layoutManager = getLayoutManager(); if (layoutManager instanceof StaggeredGridLayoutManager) { int[] firstVisibleItems = null; firstVisibleItems = ((StaggeredGridLayoutManager) layoutManager). findFirstCompletelyVisibleItemPositions(firstVisibleItems); int position = firstVisibleItems[0]; return position == 0; } else if (layoutManager instanceof LinearLayoutManager) { int position = ((LinearLayoutManager) layoutManager).findFirstCompletelyVisibleItemPosition(); return position == 0; } return false; } /** * 最后一个条目是否可见 * * @param lineNum 行数 * @param allItemNum item总数 * @return 可见返回true，不可见返回false */ public boolean isLastItemVisible(int lineNum, int allItemNum) { LayoutManager layoutManager = getLayoutManager(); if (layoutManager instanceof StaggeredGridLayoutManager) { int[] lastVisibleItems = null; lastVisibleItems = ((StaggeredGridLayoutManager) layoutManager).findLastCompletelyVisibleItemPositions(lastVisibleItems); int position = lastVisibleItems[0]; LogUtil.i(this, "lastVisiblePosition:" + position); boolean isVisible = position >= (allItemNum - lineNum); if (isVisible) { scrollBy(1, 0); } return isVisible; } else if (layoutManager instanceof LinearLayoutManager) { int position = ((LinearLayoutManager) layoutManager).findLastCompletelyVisibleItemPosition(); return position == allItemNum - 1; } return false; }</code></pre> <p>下面说一个坑，在处理最后一个条目时可见时，我发现拿到的数据并不是一种情况，当一共有三行时。</p> <p>用下面的代码来打出位置：</p> <pre> <code class="language-java">for (int i = 0; i < lastVisibleItems.length; i++) { LogUtil.i(this, "order:"+i +"----->last position:" + lastVisibleItems[i]); }</code></pre> <p>有三种情况：</p> <p>1.最后一列只有有一个时，打出的log是</p> <pre> <code class="language-java">01-06 02:40:51.868 4135-4135/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:0----->last position:12 01-06 02:40:51.869 4135-4135/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:1----->last position:10 01-06 02:40:51.869 4135-4135/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:2----->last position:11</code></pre> <p>2.当最后一列有两个时：</p> <pre> <code class="language-java">01-06 02:41:54.285 6109-6109/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:0----->last position:12 01-06 02:41:54.286 6109-6109/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:1----->last position:13 01-06 02:41:54.286 6109-6109/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:2----->last position:11</code></pre> <p>3.当最后一行有三个时：</p> <pre> <code class="language-java">01-06 02:43:21.336 8818-8818/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:0----->last position:12 01-06 02:43:21.337 8818-8818/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:1----->last position:13 01-06 02:43:21.337 8818-8818/com.songwenju.customtvrecyclerview I/swjCustomRecyclerView: order:2----->last position:14</code></pre> <p>所以这里的处理是传入行数：</p> <pre> <code class="language-java">boolean isVisible = position >= (allItemNum - lineNum);来判断是否可见。</code></pre> <p>7.在Recycler滚动时候去处理箭头的显示状态：</p> <pre> <code class="language-java">private class MyOnScrollListener extends RecyclerView.OnScrollListener { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); } @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); //在滚动的时候处理箭头的状态 setLeftArrStatus(); setRightArrStatus(); } }</code></pre> <p>来自：http://www.jianshu.com/p/566bd6188f4d</p> <p> </p>