Feature: prevent app change media volume

PlayTools.xcodeproj/project.pbxproj

@@ -84,6 +84,7 @@
 		B46C02C72C634AB5007637AB /* BatteryLevel.m in Sources */ = {isa = PBXBuildFile; fileRef = B46C02C62C634AB5007637AB /* BatteryLevel.m */; };
 		B66E65002C936EA100E48FD0 /* PlayedAppleDBConstants.swift in Sources */ = {isa = PBXBuildFile; fileRef = B66E64FF2C936E9800E48FD0 /* PlayedAppleDBConstants.swift */; };
 		B6D774FF2ACFC3D900C0D9D8 /* SwordRPC in Frameworks */ = {isa = PBXBuildFile; productRef = B6D774FE2ACFC3D900C0D9D8 /* SwordRPC */; };
+		D04B12CA2EF6F3DD008FEC14 /* MediaVolume.m in Sources */ = {isa = PBXBuildFile; fileRef = D04B12C92EF6F3DD008FEC14 /* MediaVolume.m */; };
 		EEB248592B81D074000C230A /* PlayedAppleDB.swift in Sources */ = {isa = PBXBuildFile; fileRef = EEB248582B81D074000C230A /* PlayedAppleDB.swift */; };
 /* End PBXBuildFile section */
 
@@ -183,6 +184,8 @@
 		B46C02C62C634AB5007637AB /* BatteryLevel.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = BatteryLevel.m; sourceTree = "<group>"; };
 		B46C02C82C634C60007637AB /* BatteryLevel.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = BatteryLevel.h; sourceTree = "<group>"; };
 		B66E64FF2C936E9800E48FD0 /* PlayedAppleDBConstants.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlayedAppleDBConstants.swift; sourceTree = "<group>"; };
+		D04B12C92EF6F3DD008FEC14 /* MediaVolume.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MediaVolume.m; sourceTree = "<group>"; };
+		D04B12CC2EF6F3F9008FEC14 /* MediaVolume.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MediaVolume.h; sourceTree = "<group>"; };
 		EEB248582B81D074000C230A /* PlayedAppleDB.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlayedAppleDB.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -480,6 +483,8 @@
 				6E7663A428D0FEBE00DE4AF9 /* AKPluginLoader.swift */,
 				B46C02C62C634AB5007637AB /* BatteryLevel.m */,
 				B46C02C82C634C60007637AB /* BatteryLevel.h */,
+				D04B12C92EF6F3DD008FEC14 /* MediaVolume.m */,
+				D04B12CC2EF6F3F9008FEC14 /* MediaVolume.h */,
 			);
 			path = Utils;
 			sourceTree = "<group>";
@@ -729,6 +734,7 @@
 				AA71970D287A44D200623C15 /* PlaySettings.swift in Sources */,
 				95D474FB2C0BA77B0072797F /* JoystickElement.swift in Sources */,
 				AA719759287A480D00623C15 /* PlayAction.swift in Sources */,
+				D04B12CA2EF6F3DD008FEC14 /* MediaVolume.m in Sources */,
 				954389C82B392D5300B063BB /* Button.swift in Sources */,
 				6E7663A528D0FEBE00DE4AF9 /* AKPluginLoader.swift in Sources */,
 				9562D16F2AB50D34002C329D /* ActionDispatcher.swift in Sources */,

PlayTools/Utils/MediaVolume.h

@@ -0,0 +1,18 @@
+//
+//  MediaVolume.h
+//  PlayTools
+//
+//  Created by Undefined on 2025/12/20.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSObject (SwizzleVolume)
+
+- (void)swizzleInstanceMethod:(SEL)origSelector withMethod:(SEL)newSelector;
+
+@end
+
+NS_ASSUME_NONNULL_END

PlayTools/Utils/MediaVolume.m

@@ -0,0 +1,75 @@
+//
+//  MediaVolume.m
+//  PlayTools
+//
+//  Created by Undefined on 2025/12/20.
+//
+
+#import <MediaPlayer/MediaPlayer.h>
+#import <objc/runtime.h>
+#import <PlayTools/PlayTools-Swift.h>
+#import "MediaVolume.h"
+
+__attribute__((visibility("hidden")))
+@interface MediaVolumeLoader : NSObject
+@end
+
+@implementation NSObject (SwizzleVolume)
+
+- (void)swizzleInstanceMethod:(SEL)origSelector withMethod:(SEL)newSelector {
+    Class cls = [self class];
+    // If current class doesn't exist selector, then get super
+    Method originalMethod = class_getInstanceMethod(cls, origSelector);
+    Method swizzledMethod = class_getInstanceMethod(cls, newSelector);
+
+    // Add selector if it doesn't exist, implement append with method
+    if (class_addMethod(cls,
+                        origSelector,
+                        method_getImplementation(swizzledMethod),
+                        method_getTypeEncoding(swizzledMethod))) {
+        // Replace class instance method, added if selector not exist
+        // For class cluster, it always adds new selector here
+        class_replaceMethod(cls,
+                            newSelector,
+                            method_getImplementation(originalMethod),
+                            method_getTypeEncoding(originalMethod));
+    } else {
+        // SwizzleMethod maybe belongs to super
+        class_replaceMethod(cls,
+                            newSelector,
+                            class_replaceMethod(cls,
+                                                origSelector,
+                                                method_getImplementation(swizzledMethod),
+                                                method_getTypeEncoding(swizzledMethod)),
+                            method_getTypeEncoding(originalMethod));
+    }
+}
+
+- (float)pm_get_volume {
+    return 0.3f;
+}
+
+- (void)pm_set_volume:(float)value {
+    return;
+}
+
+- (void)pm_set_volume:(float)value animated:(BOOL)animated {
+    return;
+}
+
+@end
+
+@implementation MediaVolumeLoader
+
++ (void)load {
+    [objc_getClass("AVAudioSession") swizzleInstanceMethod:@selector(outputVolume) withMethod:@selector(pm_get_volume)];
+
+    [objc_getClass("MPVolumeSlider") swizzleInstanceMethod:@selector(value) withMethod:@selector(pm_get_volume)];
+    [objc_getClass("MPVolumeSlider") swizzleInstanceMethod:@selector(setValue:) withMethod:@selector(pm_set_volume:)];
+    [objc_getClass("MPVolumeSlider") swizzleInstanceMethod:@selector(setValue:animated:) withMethod:@selector(pm_set_volume:animated:)];
+
+    [objc_getClass("MPMusicPlayerController") swizzleInstanceMethod:@selector(volume) withMethod:@selector(pm_get_volume)];
+    [objc_getClass("MPMusicPlayerController") swizzleInstanceMethod:@selector(setVolume:) withMethod:@selector(pm_set_volume:)];
+}
+
+@end