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https://github.com/Swiftgram/Telegram-iOS.git
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21bebb9d29
Introduces ASLayoutRangeModeVisibleOnly, allowing the preservation of decoded backing stores without any extra padding to strictly minimize memory usage while supporting immediate re-display of content. Set visible range controllers to this mode upon app suspend / memory warning, while more aggressively clearing others to the ASLayoutRangeModeLowMemory mode. By default, when the app is running and recieves a memory warning, we set the range mode for non-visible controllers to ASLayoutRangeModeVisibleOnly. This is because, unlike in the app suspend case where on app resume we can restore controllers from LowMemory to VisibleOnly, the memory warning doesn't provide a good opportunity to do this. A new +Beta API to control this behavior is called +setRangeModeForMemoryWarnings:, as some apps may prefer to use LowMemory in the memory warning scenario. For these apps, optimal user experience will require manually setting the range mode back to some larger value as the user navigates the app, or they will encounter controllers that are temporarily blank and need a moment to re-display their contents as they start to become visible.
59 lines
2.6 KiB
Objective-C
59 lines
2.6 KiB
Objective-C
/* Copyright (c) 2014-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*/
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#import <Foundation/Foundation.h>
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/**
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* Each mode has a complete set of tuning parameters for range types.
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* Depending on some conditions (including interface state and direction of the scroll view, state of rendering engine, etc),
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* a range controller can choose which mode it should use at a given time.
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*/
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typedef NS_ENUM(NSUInteger, ASLayoutRangeMode) {
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/**
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* Minimum mode is used when a range controller should limit the amount of work it performs.
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* Thus, fewer views/layers are created and less data is fetched, saving system resources.
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* Range controller can automatically switch to full mode when conditions change.
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*/
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ASLayoutRangeModeMinimum = 0,
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/**
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* Normal/Full mode that a range controller uses to provide the best experience for end users.
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* This mode is usually used for an active scroll view.
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* A range controller under this requires more resources compare to minimum mode.
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*/
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ASLayoutRangeModeFull,
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/**
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* Visible Only mode is used when a range controller should set its display and fetch data regions to only the size of their bounds.
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* This causes all additional backing stores & fetched data to be released, while ensuring a user revisiting the view will
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* still be able to see the expected content. This mode is automatically set on all ASRangeControllers when the app suspends,
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* allowing the operating system to keep the app alive longer and increase the chance it is still warm when the user returns.
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*/
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ASLayoutRangeModeVisibleOnly,
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/**
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* Low Memory mode is used when a range controller should discard ALL graphics buffers, including for the area that would be visible
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* the next time the user views it (bounds). The only range it preserves is Fetch Data, which is limited to the bounds, allowing
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* the content to be restored relatively quickly by re-decoding images (the compressed images are ~10% the size of the decoded ones,
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* and text is a tiny fraction of its rendered size).
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*/
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ASLayoutRangeModeLowMemory,
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ASLayoutRangeModeCount
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};
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#define ASLayoutRangeModeInvalid ASLayoutRangeModeCount
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typedef NS_ENUM(NSInteger, ASLayoutRangeType) {
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ASLayoutRangeTypeDisplay,
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ASLayoutRangeTypeFetchData,
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ASLayoutRangeTypeCount
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};
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#define ASLayoutRangeTypeRender ASLayoutRangeTypeDisplay
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#define ASLayoutRangeTypePreload ASLayoutRangeTypeFetchData
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