Awesome

FocusLayoutManager

有焦点item的水平/垂直滚动RecyclerView-LayoutManager。仿Android豆瓣书影音“推荐“频道列表布局

效果

<br/> 截图: <br/>

<br/> GIF: <br/>

<br/> 可自己监听滚动编写效果，如修改成仿MacOS文件浏览: <br/> <img src="https://github.com/CCY0122/FocusLayoutManager/blob/master/pic/gif_mac_os.gif" width=660 />

依赖

implementation 'com.ccy:FocusLayoutManager:1.0.2'
// （or api）

使用

 focusLayoutManager =
                new FocusLayoutManager.Builder()
                        .layerPadding(dp2px(this, 14))
                        .normalViewGap(dp2px(this, 14))
                        .focusOrientation(FocusLayoutManager.FOCUS_LEFT)
                        .isAutoSelect(true)
                        .maxLayerCount(3)
                        .setOnFocusChangeListener(new FocusLayoutManager.OnFocusChangeListener() {
                            @Override
                            public void onFocusChanged(int focusdPosition, int lastFocusdPosition) {
                                
                            }
                        })
                        .build();
recyclerView.setLayoutManager(focusLayoutManager);

各属性意义见图：<br/> <img src="https://github.com/CCY0122/FocusLayoutManager/blob/master/pic/detail.png" width=600 /> <br/> 注意：因为item在不同区域随着滑动会有不同的缩放（受动画控制），所以实际视觉上堆叠view的间距、普通view的间距未必等于layerPadding、normalViewGap

调整动画效果：

                new FocusLayoutManager.Builder()
                        ......
                        .setSimpleTrasitionListener(new FocusLayoutManager.SimpleTrasitionListener() {
                             @Override
                            public float getLayerViewMaxAlpha(int maxLayerCount) {
                                return super.getLayerViewMaxAlpha(maxLayerCount);
                            }

                            @Override
                            public float getLayerViewMinAlpha(int maxLayerCount) {
                                return super.getLayerViewMinAlpha(maxLayerCount);
                            }

                            @Override
                            public float getLayerChangeRangePercent() {
                                return super.getLayerChangeRangePercent();
                            }
                            //and more
                            
                            //更多可重写方法和释义见接口声明
                        })
                        .build();

自定义动画/滚动监听：

如果你想在滑动时不仅仅改变item的大小、透明度，你有更多的想法，可以监听TrasitionListener,该监听暴露了很多关键布局数据，

            ......
            .setSimpleTrasitionListener(null) //如果默认动画不想要，移除之。or use removeTrasitionlistener(XXX) 
            .addTrasitionListener(new FocusLayoutManager.TrasitionListener() {
                            @Override
                            public void handleLayerView(FocusLayoutManager focusLayoutManager,
                                                        View view, int viewLayer,
                                                        int maxLayerCount, int position,
                                                        float fraction, float offset) {
                                
                            }

                            @Override
                            public void handleFocusingView(FocusLayoutManager focusLayoutManager,
                                                           View view, int position,
                                                           float fraction, float offset) {

                            }

                            @Override
                            public void handleNormalView(FocusLayoutManager focusLayoutManager, View view, int position, float fraction, float offset) {

                            }
                        })

各参数意义见接口注释。 实际上SimpleTrasitionListener内部就会被转为TrasitionListener。可参考转换类是怎么做的：TrasitionListenerConvert

源码解析

https://blog.csdn.net/ccy0122/article/details/90515386