From a16ab7969d98b1e05ac896a4b9aa834cdac8734e Mon Sep 17 00:00:00 2001
From: Linus <23507341+Linus789@users.noreply.github.com>
Date: Sun, 8 Jan 2023 22:23:54 +0100
Subject: [PATCH] feat: `remove-screenshot-restriction` patch (#1455)

Co-authored-by: Linus789 <Linus789@users.noreply.github.com>
Co-authored-by: oSumAtrIX <johan.melkonyan1@web.de>
---
 .../patch/RemoveScreenshotRestrictionPatch.kt | 106 ++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 src/main/kotlin/app/revanced/patches/all/screenshot/removerestriction/patch/RemoveScreenshotRestrictionPatch.kt

diff --git a/src/main/kotlin/app/revanced/patches/all/screenshot/removerestriction/patch/RemoveScreenshotRestrictionPatch.kt b/src/main/kotlin/app/revanced/patches/all/screenshot/removerestriction/patch/RemoveScreenshotRestrictionPatch.kt
new file mode 100644
index 000000000..c3d2f86ec
--- /dev/null
+++ b/src/main/kotlin/app/revanced/patches/all/screenshot/removerestriction/patch/RemoveScreenshotRestrictionPatch.kt
@@ -0,0 +1,106 @@
+package app.revanced.patches.all.screenshot.removerestriction.patch
+
+import app.revanced.extensions.findMutableMethodOf
+import app.revanced.patcher.annotation.Description
+import app.revanced.patcher.annotation.Name
+import app.revanced.patcher.annotation.Version
+import app.revanced.patcher.data.BytecodeContext
+import app.revanced.patcher.extensions.replaceInstruction
+import app.revanced.patcher.patch.BytecodePatch
+import app.revanced.patcher.patch.PatchResult
+import app.revanced.patcher.patch.PatchResultSuccess
+import app.revanced.patcher.patch.annotations.Patch
+import app.revanced.patcher.util.proxy.mutableTypes.MutableMethod
+import org.jf.dexlib2.Opcode
+import org.jf.dexlib2.iface.instruction.formats.Instruction35c
+import org.jf.dexlib2.iface.reference.MethodReference
+
+@Patch(false)
+@Name("remove-screenshot-restriction")
+@Description("Removes the restriction of making screenshots.")
+@Version("0.0.1")
+class RemoveScreenshotRestrictionPatch : BytecodePatch() {
+
+    private companion object {
+        const val INTEGRATIONS_CLASS_DESCRIPTOR = "Lapp/revanced/all/screenshot/removerestriction/RemoveScreenshotRestrictionPatch;"
+    }
+
+    // Information about method calls we want to replace
+    private enum class MethodCall(
+        val definedClassName: String,
+        val methodName: String,
+        val replacementMethodDefinition: String
+    ) {
+        SetFlags(
+            "Landroid/view/Window;",
+            "setFlags",
+            "setFlags(Landroid/view/Window;II)V",
+        );
+
+        fun replaceInstruction(method: MutableMethod, instruction: Instruction35c, instructionIndex: Int) {
+            when (this) {
+                SetFlags -> {
+                    method.replaceInstruction(
+                        instructionIndex,
+                        "invoke-static { v${instruction.registerC}, v${instruction.registerD}, v${instruction.registerE} }, ${INTEGRATIONS_CLASS_DESCRIPTOR}->${replacementMethodDefinition}"
+                    )
+                }
+            }
+        }
+
+        companion object {
+            fun fromMethodReference(methodReference: MethodReference) = values().firstOrNull { search ->
+                search.definedClassName == methodReference.definingClass && search.methodName == methodReference.name
+            }
+        }
+    }
+
+    override fun execute(context: BytecodeContext): PatchResult {
+        // Find all instructions where one of the methods is called
+        buildMap {
+            context.classes.forEach { classDef ->
+                if (classDef.type == INTEGRATIONS_CLASS_DESCRIPTOR) {
+                    // avoid infinite recursion
+                    return@forEach
+                }
+
+                classDef.methods.let { methods ->
+                    buildMap methodList@{
+                        methods.forEach methods@{ method ->
+                            with(method.implementation?.instructions ?: return@methods) {
+                                ArrayDeque<Triple<MethodCall, Instruction35c, Int>>().also { patchIndices ->
+                                    this.forEachIndexed { index, instruction ->
+                                        if (instruction.opcode != Opcode.INVOKE_VIRTUAL) return@forEachIndexed
+
+                                        val invokeInstruction = instruction as Instruction35c
+                                        val methodRef = invokeInstruction.reference as MethodReference
+                                        val methodCall = MethodCall.fromMethodReference(methodRef) ?: return@forEachIndexed
+
+                                        patchIndices.add(Triple(methodCall, invokeInstruction, index))
+                                    }
+                                }.also { if (it.isEmpty()) return@methods }.let { patches ->
+                                    put(method, patches)
+                                }
+                            }
+                        }
+                    }
+                }.also { if (it.isEmpty()) return@forEach }.let { methodPatches ->
+                    put(classDef, methodPatches)
+                }
+            }
+        }.forEach { (classDef, methods) ->
+            // And finally replace the instructions...
+            with(context.proxy(classDef).mutableClass) {
+                methods.forEach { (method, patches) ->
+                    val mutableMethod = findMutableMethodOf(method)
+                    while (!patches.isEmpty()) {
+                        val (methodType, instruction, instructionIndex) = patches.removeLast()
+                        methodType.replaceInstruction(mutableMethod, instruction, instructionIndex)
+                    }
+                }
+            }
+        }
+
+        return PatchResultSuccess()
+    }
+}