Fix misplaced cursor on LB/LR paging on specific conditions

es-app/src/components/TextListComponent.h

@@ -30,6 +30,7 @@ class TextListComponent : public IList<TextListData, T>
 	using IList<TextListData, T>::getTransform;
 	using IList<TextListData, T>::mSize;
 	using IList<TextListData, T>::mCursor;
+	using IList<TextListData, T>::mViewportTop;
 	using IList<TextListData, T>::Entry;
 
 public:
@@ -92,7 +93,7 @@ class TextListComponent : public IList<TextListData, T>
 	Alignment mAlignment;
 	float mHorizontalMargin;
 
-	int getFirstVisibleEntry();
+	int viewportTop();
 	std::function<void(CursorState state)> mCursorChangedCallback;
 
 	std::shared_ptr<Font> mFont;
@@ -107,10 +108,8 @@ class TextListComponent : public IList<TextListData, T>
 	std::string mScrollSound;
 	static const unsigned int COLOR_ID_COUNT = 2;
 	unsigned int mColors[COLOR_ID_COUNT];
-	unsigned int mScreenCount;
-	int mStartEntry = 0;
-	unsigned int mCursorPrev = -1;
-	bool mOneEntryUpDn = true;
+	int mViewportHeight;
+	int mCursorPrev = -1;
 
 	ImageComponent mSelectorImage;
 };
@@ -151,32 +150,33 @@ void TextListComponent<T>::render(const Transform4x4f& parentTrans)
 
 	const float entrySize = Math::max(font->getHeight(1.0), (float)font->getSize()) * mLineSpacing;
 
-	// number of entries that can fit on the screen simultaniously
-	mScreenCount = (int)(mSize.y() / entrySize);
+	// number of listentries that can fit on the screen
+	mViewportHeight = (int)(mSize.y() / entrySize);
 
+	if(mViewportTop == -1)
+	{
+		// returning from screen saver activated game launch
+		mViewportTop = mCursor - mViewportHeight/2;
+	}
 	if(mCursor != mCursorPrev)
 	{
-		mStartEntry = (size() > mScreenCount) ? getFirstVisibleEntry() : 0;
+		mViewportTop = (size() > mViewportHeight) ? viewportTop() : 0;
 		mCursorPrev = mCursor;
 	}
 
-	unsigned int listCutoff = mStartEntry + mScreenCount;
+	unsigned int listCutoff = mViewportTop + mViewportHeight;
 	if(listCutoff > size())
 		listCutoff = size();
 
-	float y = (mSize.y() - (mScreenCount * entrySize)) * 0.5f;
+	float y = (mSize.y() - (mViewportHeight * entrySize)) * 0.5f;
 
-	// draw selector bar
-	if(mStartEntry < listCutoff)
-	{
-		if (mSelectorImage.hasImage()) {
-			mSelectorImage.setPosition(0.f, y + (mCursor - mStartEntry)*entrySize + mSelectorOffsetY, 0.f);
-			mSelectorImage.render(trans);
-		} else {
-			Renderer::setMatrix(trans);
-			Renderer::drawRect(0.0f, y + (mCursor - mStartEntry)*entrySize + mSelectorOffsetY, mSize.x(),
-					mSelectorHeight, mSelectorColor, mSelectorColorEnd, mSelectorColorGradientHorizontal);
-		}
+	if (mSelectorImage.hasImage()) {
+		mSelectorImage.setPosition(0.f, y + (mCursor - mViewportTop)*entrySize + mSelectorOffsetY, 0.f);
+		mSelectorImage.render(trans);
+	} else {
+		Renderer::setMatrix(trans);
+		Renderer::drawRect(0.0f, y + (mCursor - mViewportTop)*entrySize + mSelectorOffsetY, mSize.x(),
+			mSelectorHeight, mSelectorColor, mSelectorColorEnd, mSelectorColorGradientHorizontal);
 	}
 
 	// clip to inside margins
@@ -185,7 +185,7 @@ void TextListComponent<T>::render(const Transform4x4f& parentTrans)
 	Renderer::pushClipRect(Vector2i((int)(trans.translation().x() + mHorizontalMargin), (int)trans.translation().y()),
 		Vector2i((int)(dim.x() - mHorizontalMargin*2), (int)dim.y()));
 
-	for(int i = mStartEntry; i < listCutoff; i++)
+	for(int i = mViewportTop; i < listCutoff; i++)
 	{
 		typename IList<TextListData, T>::Entry& entry = mEntries.at((unsigned int)i);
 
@@ -254,91 +254,65 @@ void TextListComponent<T>::render(const Transform4x4f& parentTrans)
 
 
 template <typename T>
-int TextListComponent<T>::getFirstVisibleEntry()
+int TextListComponent<T>::viewportTop()
 {
+	int viewportTopMax = size() - mViewportHeight;
+	int topNew = mViewportTop;
+
 	if (mCursorPrev == -1)
-	{
-		// init or returned from emulator
 		mCursorPrev = mCursor;
-		int quot = div(mCursor, mScreenCount).quot;
-		mStartEntry = quot * mScreenCount;
-	}
-	int screenRelCursor = mCursorPrev - mStartEntry;
-	bool cursorCentered = screenRelCursor == mScreenCount/2;
-	int visibleEntryMax = size() - mScreenCount;
-	int firstVisibleEntry = 0;
 
-	if(Settings::getInstance()->getBool("UseFullscreenPaging") && !cursorCentered)
+	int delta = mCursor - mCursorPrev;
+
+	if(Settings::getInstance()->getBool("UseFullscreenPaging"))
 	{
-		// keep visible cursor constant but move visible list (default)
-		firstVisibleEntry = mCursor - screenRelCursor;
-		if(mOneEntryUpDn)
+		// delta may be greater/less than +/-mViewportHeight on re-sorting of list
+		if (delta <= -mViewportHeight || delta >= mViewportHeight
+			// keep cursor sticky at position unless the user navigates
+			// to the middle of the viewport
+			|| delta < 0 && mCursor - mViewportTop < mViewportHeight/2
+			|| delta > 0 && mCursor - mViewportTop > mViewportHeight/2)
 		{
-			int delta = mCursor - mCursorPrev;
-			// detect rollover (== delta is more than one item)
-			if(delta < -3)
-				firstVisibleEntry = 0;
-			else if(delta > 3)
-				firstVisibleEntry = visibleEntryMax;
-			else if(screenRelCursor < mScreenCount/2 && delta > 0 /*down pressed*/
-				|| screenRelCursor > mScreenCount/2 && delta < 0 /*up pressed*/)
-				// cases for list begin / list end
-				// move visible cursor and keep visible list section constant
-				firstVisibleEntry = firstVisibleEntry - delta;
+			topNew += delta;
 		}
-	} else {
-		// cursor always in middle of visible list
-		firstVisibleEntry = mCursor - mScreenCount/2;
+		// no match above will place the cursor more towards the middle
 	}
-	// bounds check
-	if(firstVisibleEntry < 0)
-		firstVisibleEntry = 0;
-	else if(firstVisibleEntry > visibleEntryMax)
-		firstVisibleEntry = visibleEntryMax;
-	return firstVisibleEntry;
+	else
+		// put cursor in middle of visible list
+		topNew = mCursor - mViewportHeight/2;
+
+	if (mCursor <= mViewportHeight/2)
+		topNew = 0;
+	else if (mCursor >= viewportTopMax + mViewportHeight/2)
+		topNew = viewportTopMax;
+
+	return topNew;
 }
 
 template <typename T>
 bool TextListComponent<T>::input(InputConfig* config, Input input)
 {
-	if(size() > 0)
+	bool isSingleStep = config->isMappedLike("down", input) || config->isMappedLike("up", input);
+	bool isPageStep = config->isMappedLike("rightshoulder", input) || config->isMappedLike("leftshoulder", input);
+
+	if(size() > 0 && (isSingleStep || isPageStep))
 	{
 		if(input.value != 0)
 		{
-			if(config->isMappedLike("down", input))
-			{
-				listInput(1);
-				mOneEntryUpDn = true;
-				return true;
-			}
-
-			if(config->isMappedLike("up", input))
-			{
-				listInput(-1);
-				mOneEntryUpDn = true;
-				return true;
-			}
-			if(config->isMappedLike("rightshoulder", input))
-			{
-				int delta = Settings::getInstance()->getBool("UseFullscreenPaging") ? mScreenCount : 10;
-				listInput(delta);
-				mOneEntryUpDn = false;
-				return true;
-			}
-
-			if(config->isMappedLike("leftshoulder", input))
+			int delta;
+			mCursorPrev = mCursor;
+			if(isSingleStep)
+				delta = config->isMappedLike("down", input) ? 1 : -1;
+			else
 			{
-				int delta = Settings::getInstance()->getBool("UseFullscreenPaging") ? mScreenCount : 10;
-				listInput(-delta);
-				mOneEntryUpDn = false;
-				return true;
+				delta = Settings::getInstance()->getBool("UseFullscreenPaging") ? mViewportHeight : 10;
+				if (config->isMappedLike("leftshoulder", input))
+					delta = -delta;
 			}
+			listInput(delta);
+			return true;
 		}else{
-			if(config->isMappedLike("down", input) || config->isMappedLike("up", input) ||
-				config->isMappedLike("rightshoulder", input) || config->isMappedLike("leftshoulder", input))
-			{
-				stopScrolling();
-			}
+			stopScrolling();
 		}
 	}
 

es-app/src/views/ViewController.cpp

@@ -247,8 +247,10 @@ void ViewController::launch(FileData* game, Vector3f center)
 			game->launchGame(mWindow);
 			setAnimation(new LambdaAnimation(fadeFunc, 800), 0, [this] { mLockInput = false; }, true);
 			this->onFileChanged(game, FILE_METADATA_CHANGED);
-			if (mCurrentView)
+			if (mCurrentView) {
+				this->getGameListView(game->getSystem())->setViewportTop(-1);
 				mCurrentView->onShow();
+			}
 		});
 	} else if (transition_style == "slide"){
 		// move camera to zoom in on center + fade out, launch game, come back in
@@ -258,8 +260,10 @@ void ViewController::launch(FileData* game, Vector3f center)
 			mCamera = origCamera;
 			setAnimation(new LaunchAnimation(mCamera, mFadeOpacity, center, 600), 0, [this] { mLockInput = false; }, true);
 			this->onFileChanged(game, FILE_METADATA_CHANGED);
-			if (mCurrentView)
+			if (mCurrentView) {
+				this->getGameListView(game->getSystem())->setViewportTop(-1);
 				mCurrentView->onShow();
+			}
 		});
 	} else { // instant
 		setAnimation(new LaunchAnimation(mCamera, mFadeOpacity, center, 10), 0, [this, origCamera, center, game]
@@ -268,8 +272,10 @@ void ViewController::launch(FileData* game, Vector3f center)
 			mCamera = origCamera;
 			setAnimation(new LaunchAnimation(mCamera, mFadeOpacity, center, 10), 0, [this] { mLockInput = false; }, true);
 			this->onFileChanged(game, FILE_METADATA_CHANGED);
-			if (mCurrentView)
+			if (mCurrentView) {
+				this->getGameListView(game->getSystem())->setViewportTop(-1);
 				mCurrentView->onShow();
+			}
 		});
 	}
 }
@@ -477,6 +483,7 @@ void ViewController::reloadGameListView(IGameListView* view, bool reloadTheme)
 			bool isCurrent = (mCurrentView == it->second);
 			SystemData* system = it->first;
 			FileData* cursor = view->getCursor();
+			int viewportTop = view->getViewportTop();
 			mGameListViews.erase(it);
 
 			if(reloadTheme)
@@ -487,6 +494,7 @@ void ViewController::reloadGameListView(IGameListView* view, bool reloadTheme)
 			// to counter having come from a placeholder
 			if (!cursor->isPlaceHolder()) {
 				newView->setCursor(cursor);
+				newView->setViewportTop(viewportTop);
 			}
 			if(isCurrent)
 				mCurrentView = newView;
@@ -504,9 +512,11 @@ void ViewController::reloadAll()
 {
 	// clear all gamelistviews
 	std::map<SystemData*, FileData*> cursorMap;
+	std::map<SystemData*, int> viewportTopMap;
 	for(auto it = mGameListViews.cbegin(); it != mGameListViews.cend(); it++)
 	{
 		cursorMap[it->first] = it->second->getCursor();
+		viewportTopMap[it->first] = it->second->getViewportTop();
 	}
 	mGameListViews.clear();
 
@@ -519,6 +529,12 @@ void ViewController::reloadAll()
 		getGameListView(it->first)->setCursor(it->second);
 	}
 
+	// restore index of first list item on display
+	for(auto it = viewportTopMap.cbegin(); it != viewportTopMap.cend(); it++)
+	{
+		getGameListView(it->first)->setViewportTop(it->second);
+	}
+
 	// Rebuild SystemListView
 	mSystemListView.reset();
 	getSystemListView();

es-app/src/views/gamelist/BasicGameListView.cpp

@@ -90,6 +90,17 @@ void BasicGameListView::setCursor(FileData* cursor)
 	}
 }
 
+void BasicGameListView::setViewportTop(int index)
+{
+	mList.setViewportTop(index);
+}
+
+
+int BasicGameListView::getViewportTop()
+{
+	return mList.getViewportTop();
+}
+
 void BasicGameListView::addPlaceholder()
 {
 	// empty list - add a placeholder

es-app/src/views/gamelist/BasicGameListView.h

@@ -17,6 +17,8 @@ class BasicGameListView : public ISimpleGameListView
 
 	virtual FileData* getCursor() override;
 	virtual void setCursor(FileData* file) override;
+	virtual int getViewportTop() override;
+	virtual void setViewportTop(int index) override;
 
 	virtual const char* getName() const override { return "basic"; }
 

es-app/src/views/gamelist/GridGameListView.h

@@ -21,6 +21,8 @@ class GridGameListView : public ISimpleGameListView
 
 	virtual FileData* getCursor() override;
 	virtual void setCursor(FileData*) override;
+	virtual void setViewportTop(int index) { ; }
+	virtual int getViewportTop() { return -1; }
 
 	virtual bool input(InputConfig* config, Input input) override;
 

es-app/src/views/gamelist/IGameListView.h

@@ -31,6 +31,8 @@ class IGameListView : public GuiComponent
 
 	virtual FileData* getCursor() = 0;
 	virtual void setCursor(FileData*) = 0;
+	virtual int getViewportTop() = 0;
+	virtual void setViewportTop(int index) = 0;
 
 	virtual bool input(InputConfig* config, Input input) override;
 	virtual void remove(FileData* game, bool deleteFile, bool refreshView=true) = 0;

es-app/src/views/gamelist/ISimpleGameListView.h

@@ -24,6 +24,8 @@ class ISimpleGameListView : public IGameListView
 
 	virtual FileData* getCursor() = 0;
 	virtual void setCursor(FileData*) = 0;
+	virtual int getViewportTop() = 0;
+	virtual void setViewportTop(int index) = 0;
 
 	virtual bool input(InputConfig* config, Input input) override;
 	virtual void launch(FileData* game) = 0;

es-core/src/components/IList.h

@@ -59,6 +59,7 @@ class IList : public GuiComponent
 
 protected:
 	int mCursor;
+	int mViewportTop;
 
 	int mScrollTier;
 	int mScrollVelocity;
@@ -81,6 +82,7 @@ class IList : public GuiComponent
 		mGradient(window), mTierList(tierList), mLoopType(loopType)
 	{
 		mCursor = 0;
+		mViewportTop = 0;
 		mScrollTier = 0;
 		mScrollVelocity = 0;
 		mScrollTierAccumulator = 0;
@@ -158,6 +160,16 @@ class IList : public GuiComponent
 		return false;
 	}
 
+	void setViewportTop(int index)
+	{
+		mViewportTop = index;
+	}
+
+	int getViewportTop()
+	{
+		return mViewportTop;
+	}
+
 	// entry management
 	void add(const Entry& e)
 	{