Signal-iOS/Signal/src/UserInterface/WindowManagerFix.m

//
// Copyright 2018 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//

#import "WindowManagerFix.h"

#import <SignalServiceKit/SignalServiceKit-Swift.h>

void fixit_workAroundRotationIssue(UIWindow *window)
{
    // ### Symptom
    //
    // The app can get into a degraded state where the main window will incorrectly remain locked in
    // portrait mode. Worse yet, the status bar and input window will continue to rotate with respect
    // to the device orientation. So once you're in this degraded state, the status bar and input
    // window can be in landscape while simultaneoulsy the view controller behind them is in portrait.
    //
    // ### To Reproduce
    //
    // On an iPhone6 (not reproducible on an iPhoneX)
    //
    // 0. Ensure "screen protection" is enabled (not necessarily screen lock)
    // 1. Enter Conversation View Controller
    // 2. Pop Keyboard
    // 3. Begin dismissing keyboard with one finger, but stopping when it's about 50% dismissed,
    //    keep your finger there with the keyboard partially dismissed.
    // 4. With your other hand, hit the home button to leave Signal.
    // 5. Re-enter Signal
    // 6. Rotate to landscape
    //
    // Expected: Conversation View, Input Toolbar window, and Settings Bar should all rotate to landscape.
    // Actual: The input toolbar and the settings toolbar rotate to landscape, but the Conversation
    //         View remains in portrait, this looks super broken.
    //
    // ### Background
    //
    // Some debugging shows that the `ConversationViewController.view.window.isInterfaceAutorotationDisabled`
    // is true. This is a private property, whose function we don't exactly know, but it seems like
    // `interfaceAutorotation` is disabled when certain transition animations begin, and then
    // re-enabled once the animation completes.
    //
    // My best guess is that autorotation is intended to be disabled for the duration of the
    // interactive-keyboard-dismiss-transition, so when we start the interactive dismiss, autorotation
    // has been disabled, but because we hide the main app window in the middle of the transition,
    // autorotation doesn't have a chance to be re-enabled.
    //
    // ## So, The Fix
    //
    // If we find ourself in a situation where autorotation is disabled while showing the rootWindow,
    // we re-enable autorotation.

    // NSString *encodedSelectorString1 = @"isInterfaceAutorotationDisabled".encodedForSelector;
    NSString *encodedSelectorString1 = @"egVaAAZ2BHdydHZSBwYBBAEGcgZ6AQBVegVyc312dQ==";
    NSString *_Nullable selectorString1 = encodedSelectorString1.decodedForSelector;
    if (selectorString1 == nil) {
        OWSCFailDebug(@"selectorString1 was unexpectedly nil");
        return;
    }
    SEL selector1 = NSSelectorFromString(selectorString1);

    if (![window respondsToSelector:selector1]) {
        OWSCFailDebug(@"failure: doesn't respond to selector1");
        return;
    }
    IMP imp1 = [window methodForSelector:selector1];
    BOOL (*func1)(id, SEL) = (void *)imp1;
    BOOL isDisabled = func1(window, selector1);

    if (isDisabled) {
        OWSLogInfo(@"autorotation is disabled.");

        // The remainder of this method calls:
        //   [[UIScrollToDismissSupport supportForScreen:UIScreen.main] finishScrollViewTransition]
        // after verifying the methods/classes exist.

        // NSString *encodedKlassString = @"UIScrollToDismissSupport".encodedForSelector;
        NSString *encodedKlassString = @"ZlpkdAQBfX1lAVV6BX56BQVkBwICAQQG";
        NSString *_Nullable klassString = encodedKlassString.decodedForSelector;
        if (klassString == nil) {
            OWSCFailDebug(@"klassString was unexpectedly nil");
            return;
        }
        id klass = NSClassFromString(klassString);
        if (klass == nil) {
            OWSCFailDebug(@"klass was unexpectedly nil");
            return;
        }

        // NSString *encodedSelector2String = @"supportForScreen:".encodedForSelector;
        NSString *encodedSelector2String = @"BQcCAgEEBlcBBGR0BHZ2AEs=";
        NSString *_Nullable selector2String = encodedSelector2String.decodedForSelector;
        if (selector2String == nil) {
            OWSCFailDebug(@"selector2String was unexpectedly nil");
            return;
        }
        SEL selector2 = NSSelectorFromString(selector2String);
        if (![klass respondsToSelector:selector2]) {
            OWSCFailDebug(@"klass didn't respond to selector");
            return;
        }
        IMP imp2 = [klass methodForSelector:selector2];
        id (*func2)(id, SEL, UIScreen *) = (void *)imp2;
        id dismissSupport = func2(klass, selector2, UIScreen.mainScreen);

        // NSString *encodedSelector3String = @"finishScrollViewTransition".encodedForSelector;
        NSString *encodedSelector3String = @"d3oAegV5ZHQEAX19Z3p2CWUEcgAFegZ6AQA=";
        NSString *_Nullable selector3String = encodedSelector3String.decodedForSelector;
        if (selector3String == nil) {
            OWSCFailDebug(@"selector3String was unexpectedly nil");
            return;
        }
        SEL selector3 = NSSelectorFromString(selector3String);
        if (![dismissSupport respondsToSelector:selector3]) {
            OWSCFailDebug(@"dismissSupport didn't respond to selector");
            return;
        }
        IMP imp3 = [dismissSupport methodForSelector:selector3];
        void (*func3)(id, SEL) = (void *)imp3;
        func3(dismissSupport, selector3);

        OWSLogInfo(@"finished scrollView transition");
    }
}