Don't unload all media on switching between chats.

Telegram/SourceFiles/ui/image/image.cpp

@@ -42,7 +42,7 @@ int64 ComputeUsage(const QImage &image) {
 Core::MediaActiveCache<const Image> &ActiveCache() {
 	static auto Instance = Core::MediaActiveCache<const Image>(
 		kMemoryForCache,
-		[](const Image *image) { image->forget(); });
+		[](const Image *image) { image->unload(); });
 	return Instance;
 }
 
@@ -769,9 +769,9 @@ void Image::checkSource() const {
 	ActiveCache().up(this);
 }
 
-void Image::forget() const {
+void Image::unload() const {
 	_source->takeLoaded();
-	_source->forget();
+	_source->unload();
 	invalidateSizeCache();
 	ActiveCache().decrement(ComputeUsage(_data));
 	_data = QImage();
@@ -800,6 +800,6 @@ void Image::invalidateSizeCache() const {
 }
 
 Image::~Image() {
-	forget();
+	unload();
 	ActiveCache().remove(this);
 }

Telegram/SourceFiles/ui/image/image.h

@@ -54,7 +54,7 @@ public:
 		bool loadFirst,
 		bool prior) = 0;
 	virtual QImage takeLoaded() = 0;
-	virtual void forget() = 0;
+	virtual void unload() = 0;
 
 	virtual void automaticLoad(
 		Data::FileOrigin origin,
@@ -229,7 +229,7 @@ public:
 
 	bool loaded() const;
 	bool isNull() const;
-	void forget() const;
+	void unload() const;
 	void setDelayedStorageLocation(
 		Data::FileOrigin origin,
 		const StorageImageLocation &location);

Telegram/SourceFiles/ui/image/image_source.cpp

@@ -37,7 +37,7 @@ QImage ImageSource::takeLoaded() {
 	return _data;
 }
 
-void ImageSource::forget() {
+void ImageSource::unload() {
 }
 
 void ImageSource::automaticLoad(
@@ -161,7 +161,7 @@ QImage LocalFileSource::takeLoaded() {
 	return std::move(_data);
 }
 
-void LocalFileSource::forget() {
+void LocalFileSource::unload() {
 	_data = QImage();
 }
 
@@ -361,10 +361,6 @@ void RemoteSource::loadEvenCancelled(
 	return load(origin, loadFirst, prior);
 }
 
-RemoteSource::~RemoteSource() {
-	forget();
-}
-
 bool RemoteSource::displayLoading() {
 	return loaderValid()
 		&& (!_loader->loadingLocal() || !_loader->autoLoading());
@@ -380,7 +376,7 @@ void RemoteSource::cancel() {
 		std::unique_ptr<FileLoader>(loader));
 }
 
-void RemoteSource::forget() {
+void RemoteSource::unload() {
 	if (loaderValid()) {
 		destroyLoaderDelayed();
 	}
@@ -394,6 +390,10 @@ int RemoteSource::loadOffset() {
 	return loaderValid() ? _loader->currentOffset() : 0;
 }
 
+RemoteSource::~RemoteSource() {
+	unload();
+}
+
 const StorageImageLocation &RemoteSource::location() {
 	return StorageImageLocation::Null;
 }

Telegram/SourceFiles/ui/image/image_source.h

@@ -24,7 +24,7 @@ public:
 		bool loadFirst,
 		bool prior) override;
 	QImage takeLoaded() override;
-	void forget() override;
+	void unload() override;
 
 	void automaticLoad(
 		Data::FileOrigin origin,
@@ -75,7 +75,7 @@ public:
 		bool loadFirst,
 		bool prior) override;
 	QImage takeLoaded() override;
-	void forget() override;
+	void unload() override;
 
 	void automaticLoad(
 		Data::FileOrigin origin,
@@ -126,7 +126,7 @@ public:
 		bool loadFirst,
 		bool prior) override;
 	QImage takeLoaded() override;
-	void forget() override;
+	void unload() override;
 
 	void automaticLoad(
 		Data::FileOrigin origin,