Add support for partial vs full items when searching for first visibl…

…e item

README.md

@@ -6,7 +6,7 @@ Adapter and LayoutManager for Android RecyclerView which enables sticky header p
 ## Download
 minSdkVersion: 11
 ```
-compile 'org.zakariya.stickyheaders:stickyheaders:0.7.2'
+compile 'org.zakariya.stickyheaders:stickyheaders:0.7.3'
 
 ```
 

app/src/main/java/org/zakariya/stickyheadersapp/ui/DemoActivity.java

@@ -29,7 +29,7 @@ public class DemoActivity extends AppCompatActivity {
 	private static final String TAG = DemoActivity.class.getSimpleName();
 	private static final String STATE_SCROLL_POSITION = "DemoActivity.STATE_SCROLL_POSITION";
 
-	public static final boolean SHOW_ADAPTER_POSITIONS = false;
+	public static final boolean SHOW_ADAPTER_POSITIONS = true;
 
 	RecyclerView recyclerView;
 	ProgressBar progressBar;
@@ -112,10 +112,11 @@ private void showInspectDialog() {
 			return;
 		}
 
+		boolean fullVisibleOnly = true;
 		StickyHeaderLayoutManager layoutManager = (StickyHeaderLayoutManager) recyclerView.getLayoutManager();
-		SectioningAdapter.HeaderViewHolder headerViewHolder = layoutManager.getFirstVisibleHeaderViewHolder();
-		SectioningAdapter.ItemViewHolder itemViewHolder = layoutManager.getFirstVisibleItemViewHolder();
-		SectioningAdapter.FooterViewHolder footerViewHolder = layoutManager.getFirstVisibleFooterViewHolder();
+		SectioningAdapter.HeaderViewHolder headerViewHolder = layoutManager.getFirstVisibleHeaderViewHolder(fullVisibleOnly);
+		SectioningAdapter.ItemViewHolder itemViewHolder = layoutManager.getFirstVisibleItemViewHolder(fullVisibleOnly);
+		SectioningAdapter.FooterViewHolder footerViewHolder = layoutManager.getFirstVisibleFooterViewHolder(fullVisibleOnly);
 
 		ArrayList<String> inspections = new ArrayList<>();
 

stickyheaders/build.gradle

@@ -3,7 +3,7 @@ apply plugin: 'com.jfrog.bintray'
 apply plugin: 'com.github.dcendents.android-maven'
 
 group = 'org.zakariya.stickyheaders'
-version = '0.7.2'
+version = '0.7.3'
 
 android {
 	compileSdkVersion 23

stickyheaders/src/main/java/org/zakariya/stickyheaders/StickyHeaderLayoutManager.java

@@ -126,7 +126,7 @@ public Parcelable onSaveInstanceState() {
 		}
 
 		// Check if we're detached; if not, update
-		if(adapter != null)
+		if (adapter != null)
 			updateFirstAdapterPosition();
 		SavedState state = new SavedState();
 		state.firstViewAdapterPosition = firstViewAdapterPosition;
@@ -142,10 +142,10 @@ public void onRestoreInstanceState(Parcelable state) {
 		}
 
 		if (state instanceof SavedState) {
-			pendingSavedState = (SavedState)state;
+			pendingSavedState = (SavedState) state;
 			requestLayout();
 		} else {
-			Log.e(TAG, "onRestoreInstanceState: invalid saved state class, expected: " + SavedState.class.getCanonicalName() + " got: " + state.getClass().getCanonicalName() );
+			Log.e(TAG, "onRestoreInstanceState: invalid saved state class, expected: " + SavedState.class.getCanonicalName() + " got: " + state.getClass().getCanonicalName());
 		}
 	}
 
@@ -178,7 +178,7 @@ public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State
 		int totalVendedHeight = 0;
 
 		// If we emptied the view with a notify, we may overshoot and fail to draw
-		if(firstViewAdapterPosition > state.getItemCount())
+		if (firstViewAdapterPosition > state.getItemCount())
 			firstViewAdapterPosition = 0;
 
 		// walk through adapter starting at firstViewAdapterPosition stacking each vended item
@@ -320,7 +320,7 @@ public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerVi
 						isHeader = itemViewType == SectioningAdapter.TYPE_HEADER;
 
 						// If it's still a header, we don't need to do anything right now
-						if(isHeader)
+						if (isHeader)
 							break;
 					}
 
@@ -444,31 +444,34 @@ public void scrollToPosition(int position) {
 	}
 
 	/**
+	 * @param fullyVisibleOnly if true, the search will be limited to the first item not hanging off top of screen or partially obscured by a header
 	 * @return the viewholder for the first visible item (not header or footer)
 	 */
 	@Nullable
-	public SectioningAdapter.ItemViewHolder getFirstVisibleItemViewHolder() {
-		return (SectioningAdapter.ItemViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_ITEM);
+	public SectioningAdapter.ItemViewHolder getFirstVisibleItemViewHolder(boolean fullyVisibleOnly) {
+		return (SectioningAdapter.ItemViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_ITEM, fullyVisibleOnly);
 	}
 
 	/**
+	 * @param fullyVisibleOnly if true, the search will be limited to the first header not hanging off top of screen
 	 * @return the viewholder for the first visible header (not item or footer)
 	 */
 	@Nullable
-	public SectioningAdapter.HeaderViewHolder getFirstVisibleHeaderViewHolder() {
-		return (SectioningAdapter.HeaderViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_HEADER);
+	public SectioningAdapter.HeaderViewHolder getFirstVisibleHeaderViewHolder(boolean fullyVisibleOnly) {
+		return (SectioningAdapter.HeaderViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_HEADER, fullyVisibleOnly);
 	}
 
 	/**
+	 * @param fullyVisibleOnly if true, the search will be limited to the first footer not hanging off top of screen or partially obscured by a header
 	 * @return the viewholder for the first visible footer (not header or item)
 	 */
 	@Nullable
-	public SectioningAdapter.FooterViewHolder getFirstVisibleFooterViewHolder() {
-		return (SectioningAdapter.FooterViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_FOOTER);
+	public SectioningAdapter.FooterViewHolder getFirstVisibleFooterViewHolder(boolean fullyVisibleOnly) {
+		return (SectioningAdapter.FooterViewHolder) getFirstVisibleViewHolderOfType(SectioningAdapter.TYPE_FOOTER, fullyVisibleOnly);
 	}
 
 	@Nullable
-	SectioningAdapter.ViewHolder getFirstVisibleViewHolderOfType(int baseType) {
+	SectioningAdapter.ViewHolder getFirstVisibleViewHolderOfType(int baseType, boolean fullyVisibleOnly) {
 		if (getChildCount() == 0) {
 			return null;
 		}
@@ -478,7 +481,7 @@ SectioningAdapter.ViewHolder getFirstVisibleViewHolderOfType(int baseType) {
 		// our items is below this value
 		int firstHeaderBottom = 0;
 		if (baseType != SectioningAdapter.TYPE_HEADER) {
-			SectioningAdapter.HeaderViewHolder firstHeader = getFirstVisibleHeaderViewHolder();
+			SectioningAdapter.HeaderViewHolder firstHeader = getFirstVisibleHeaderViewHolder(false);
 			if (firstHeader != null) {
 				firstHeaderBottom = getDecoratedBottom(firstHeader.itemView);
 			}
@@ -501,13 +504,20 @@ SectioningAdapter.ViewHolder getFirstVisibleViewHolderOfType(int baseType) {
 				continue;
 			}
 
-			// filter out items which are fully obscured by a header
+			// filter out items which are partially or fully obscured by a header
+			int t = getDecoratedTop(v);
 			int b = getDecoratedBottom(v);
-			if (b <= firstHeaderBottom + 1) {
-				continue;
+
+			if (fullyVisibleOnly) {
+				if (t < firstHeaderBottom) {
+					continue;
+				}
+			} else {
+				if (b <= firstHeaderBottom + 1) {
+					continue;
+				}
 			}
 
-			int t = getDecoratedTop(v);
 			if (t < top) {
 				top = t;
 				topmostView = v;