diff --git a/.idea/assetWizardSettings.xml b/.idea/assetWizardSettings.xml
deleted file mode 100644
index d52f2e9..0000000
--- a/.idea/assetWizardSettings.xml
+++ /dev/null
@@ -1,47 +0,0 @@
-
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/caches/build_file_checksums.ser b/.idea/caches/build_file_checksums.ser
index 82a9c23..3923ecb 100644
Binary files a/.idea/caches/build_file_checksums.ser and b/.idea/caches/build_file_checksums.ser differ
diff --git a/.idea/checkstyle-idea.xml b/.idea/checkstyle-idea.xml
deleted file mode 100644
index 0fc9593..0000000
--- a/.idea/checkstyle-idea.xml
+++ /dev/null
@@ -1,17 +0,0 @@
-
-
-
-
-
-
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 99202cc..291ab30 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,19 @@
+
+
+
diff --git a/.idea/modules.xml b/.idea/modules.xml
index e578a09..bb34f9c 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -2,8 +2,8 @@
-
-
+
+
diff --git a/StackLayoutManager/src/main/java/com/littlemango/stacklayoutmanager/StackLayoutManager.kt b/StackLayoutManager/src/main/java/com/littlemango/stacklayoutmanager/StackLayoutManager.kt
index b41be73..8fd1e73 100644
--- a/StackLayoutManager/src/main/java/com/littlemango/stacklayoutmanager/StackLayoutManager.kt
+++ b/StackLayoutManager/src/main/java/com/littlemango/stacklayoutmanager/StackLayoutManager.kt
@@ -2,8 +2,7 @@ package com.littlemango.stacklayoutmanager
import android.support.annotation.IntRange
import android.support.v7.widget.RecyclerView
-import android.support.v7.widget.RecyclerView.SCROLL_STATE_DRAGGING
-import android.support.v7.widget.RecyclerView.SCROLL_STATE_IDLE
+import android.support.v7.widget.RecyclerView.*
import android.view.View
import android.view.ViewGroup
@@ -41,28 +40,17 @@ class StackLayoutManager(scrollOrientation: ScrollOrientation,
//fling的方向，用来判断是前翻还是后翻
private var mFlingOrientation = FlingOrientation.NONE
- init {
- mScrollOffset = when(mScrollOrientation) {
- ScrollOrientation.RIGHT_TO_LEFT, ScrollOrientation.BOTTOM_TO_TOP -> 0
- else -> Int.MAX_VALUE
- }
+ //当前所处item对应的位置
+ private var itemPosition = 0
- if (StackAnimation::class.java.isAssignableFrom(animation)) {
- try {
- val cla = animation.getDeclaredConstructor(ScrollOrientation::class.java, Int::class.javaPrimitiveType)
- mAnimation = cla.newInstance(scrollOrientation, visibleCount) as StackAnimation
- } catch (e: Exception) {
- e.printStackTrace()
- }
- }
- if (StackLayout::class.java.isAssignableFrom(layout)) {
- try {
- val cla = layout.getDeclaredConstructor(ScrollOrientation::class.java, Int::class.javaPrimitiveType, Int::class.javaPrimitiveType)
- mLayout = cla.newInstance(scrollOrientation, visibleCount, 30) as StackLayout
- } catch (e: Exception) {
- e.printStackTrace()
- }
- }
+ //判断item位置是否发生了改变
+ private var isItemPositionChanged = false
+
+ //item 位置发生改变的回调
+ private var itemChangedListener: ItemChangedListener? = null
+
+ interface ItemChangedListener {
+ fun onItemChanged(position: Int)
}
/**
@@ -173,12 +161,43 @@ class StackLayoutManager(scrollOrientation: ScrollOrientation,
}
}
+ /**
+ * 设置 item 位置改变时触发的回调
+ */
+ fun setItemChangedListener(listener: ItemChangedListener) {
+ itemChangedListener = listener
+ }
+
constructor(scrollOrientation: ScrollOrientation) : this(scrollOrientation, 3, DefaultAnimation::class.java, DefaultLayout::class.java)
constructor(scrollOrientation: ScrollOrientation, visibleCount: Int) : this(scrollOrientation, visibleCount, DefaultAnimation::class.java, DefaultLayout::class.java)
constructor() : this(ScrollOrientation.RIGHT_TO_LEFT)
+ init {
+ mScrollOffset = when(mScrollOrientation) {
+ ScrollOrientation.RIGHT_TO_LEFT, ScrollOrientation.BOTTOM_TO_TOP -> 0
+ else -> Int.MAX_VALUE
+ }
+
+ if (StackAnimation::class.java.isAssignableFrom(animation)) {
+ try {
+ val cla = animation.getDeclaredConstructor(ScrollOrientation::class.java, Int::class.javaPrimitiveType)
+ mAnimation = cla.newInstance(scrollOrientation, visibleCount) as StackAnimation
+ } catch (e: Exception) {
+ e.printStackTrace()
+ }
+ }
+ if (StackLayout::class.java.isAssignableFrom(layout)) {
+ try {
+ val cla = layout.getDeclaredConstructor(ScrollOrientation::class.java, Int::class.javaPrimitiveType, Int::class.javaPrimitiveType)
+ mLayout = cla.newInstance(scrollOrientation, visibleCount, 30) as StackLayout
+ } catch (e: Exception) {
+ e.printStackTrace()
+ }
+ }
+ }
+
override fun generateDefaultLayoutParams(): RecyclerView.LayoutParams {
return RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT)
@@ -211,7 +230,6 @@ class StackLayoutManager(scrollOrientation: ScrollOrientation,
}
}
}
-
calculateAndScrollToTarget(view)
}
return mPagerMode
@@ -293,6 +311,19 @@ class StackLayoutManager(scrollOrientation: ScrollOrientation,
scrollToCenter(position, recyclerView, true)
}
+ private fun updatePositionRecordAndNotify(position: Int) {
+ if (itemChangedListener == null) {
+ return
+ }
+ if (position != itemPosition) {
+ isItemPositionChanged = true
+ itemPosition = position
+ itemChangedListener?.onItemChanged(itemPosition)
+ } else {
+ isItemPositionChanged = false
+ }
+ }
+
private fun handleScrollBy(offset: Int, recycler: RecyclerView.Recycler): Int {
//期望值，不得超过最大最小值，所以期望值不一定等于实际值
val expectOffset = mScrollOffset + offset
@@ -333,6 +364,9 @@ class StackLayoutManager(scrollOrientation: ScrollOrientation,
mAnimation?.doAnimation(movePercent, view, i - firstVisiblePosition)
}
+ //尝试更新当前item的位置并通知外界
+ updatePositionRecordAndNotify(firstVisiblePosition)
+
//重用
if (firstVisiblePosition - 1 >= 0) {
val view = recycler.getViewForPosition(firstVisiblePosition - 1)
diff --git a/sample/src/main/java/com/littlemango/stacklayoutmanagermaster/MainActivity.java b/sample/src/main/java/com/littlemango/stacklayoutmanagermaster/MainActivity.java
index 957b82a..970b829 100644
--- a/sample/src/main/java/com/littlemango/stacklayoutmanagermaster/MainActivity.java
+++ b/sample/src/main/java/com/littlemango/stacklayoutmanagermaster/MainActivity.java
@@ -31,10 +31,13 @@ public class MainActivity extends AppCompatActivity {
private String[] selectItems;
+ private Toast mToast;
+
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
+ mToast = Toast.makeText(MainActivity.this, "", Toast.LENGTH_SHORT);
mRecyclerView = findViewById(R.id.recycleView);
mStackLayoutManager = new StackLayoutManager();
@@ -114,12 +117,18 @@ public class MainActivity extends AppCompatActivity {
.show();
}
});
+
+ mStackLayoutManager.setItemChangedListener(new StackLayoutManager.ItemChangedListener() {
+ @Override
+ public void onItemChanged(int position) {
+ mToast.setText("first visible item position is " + position);
+ mToast.show();
+ }
+ });
}
class StackLayoutAdapter extends RecyclerView.Adapter {
- Toast mToast = Toast.makeText(MainActivity.this, "", Toast.LENGTH_SHORT);
-
@NonNull
@Override
public StackHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {