fix: Readd swipe-controls patch (#123)

src/main/kotlin/app/revanced/extensions/Extensions.kt

@@ -1,7 +1,18 @@
 package app.revanced.extensions
 
+import app.revanced.patcher.data.impl.BytecodeData
+import app.revanced.patcher.extensions.addInstructions
+import app.revanced.patcher.patch.PatchResultError
+import app.revanced.patcher.util.proxy.mutableTypes.MutableMethod
 import app.revanced.patcher.util.smali.toInstruction
+import org.jf.dexlib2.AccessFlags
+import org.jf.dexlib2.Opcode
 import org.jf.dexlib2.builder.MutableMethodImplementation
+import org.jf.dexlib2.builder.instruction.BuilderInstruction11n
+import org.jf.dexlib2.builder.instruction.BuilderInstruction11x
+import org.jf.dexlib2.builder.instruction.BuilderInstruction21t
+import org.jf.dexlib2.builder.instruction.BuilderInstruction35c
+import org.jf.dexlib2.immutable.reference.ImmutableMethodReference
 import org.w3c.dom.Node
 
 internal fun MutableMethodImplementation.injectHideCall(
@@ -14,6 +25,115 @@ internal fun MutableMethodImplementation.injectHideCall(
     )
 }
 
+/**
+ * Insert an event hook at the top of the method. If the hook returns true, the event is consumed and the method will return with true
+ *
+ * the hook method MUST return a boolean and MUST take two parameters, like so:
+ *  fun hook(thisRef: Object, eventData: Object): Boolean {}
+ *
+ * The final injected code will resemble the following logic:
+ *  if( YouHook(this, event) ) { return true; }
+ *  ...
+ *
+ * @param hookRef reference to the hook method
+ */
+internal fun MutableMethod.injectConsumableEventHook(hookRef: ImmutableMethodReference) {
+    val isStaticMethod = AccessFlags.STATIC.isSet(this.accessFlags)
+    this.implementation?.let { impl ->
+        // create label to index 0 to continue to the normal program flow
+        val lblContinueNormalFlow = impl.newLabelForIndex(0)
+
+        // define registers
+        /** V0 */
+        val regV0 = 0
+
+        /** this  */
+        val regP0 = impl.registerCount - this.parameters.size - (if (isStaticMethod) 0 else 1)
+
+        /** motionEvent */
+        val regP1 = regP0 + 1
+
+        // insert instructions at the start of the method:
+        // if( Hook(this, event) ) { return true; }
+        impl.addInstructions(
+            0, listOf(
+                // invoke-static { p0, p1 } <hook>
+                BuilderInstruction35c(
+                    Opcode.INVOKE_STATIC,
+                    2,
+                    regP0,
+                    regP1,
+                    0, 0, 0,
+                    hookRef
+                ),
+
+                // move-result v0
+                BuilderInstruction11x(
+                    Opcode.MOVE_RESULT,
+                    regV0
+                ),
+
+                // if-eqz v0, :continue_normal_flow
+                BuilderInstruction21t(
+                    Opcode.IF_EQZ,
+                    regV0,
+                    lblContinueNormalFlow
+                ),
+
+                // const/4 v0, 0x1
+                BuilderInstruction11n(
+                    Opcode.CONST_4,
+                    regV0,
+                    0x1
+                ),
+
+                // return v0
+                BuilderInstruction11x(
+                    Opcode.RETURN,
+                    regV0
+                )
+
+                // :continue_normal_flow
+            )
+        )
+    }
+}
+
+/**
+ * Insert instructions into a named method
+ *
+ * @param targetClass the name of the class of which the method is a member
+ * @param targetMethod the name of the method to insert into
+ * @param index index to insert the instructions at. If the index is negative, it is used as an offset to the last method (so -1 inserts at the end of the method)
+ * @param instructions the smali instructions to insert (they'll be compiled by MutableMethod.addInstructions)
+ */
+internal fun BytecodeData.injectIntoNamedMethod(
+    targetClass: String,
+    targetMethod: String,
+    index: Int,
+    instructions: String
+) {
+    var injections = 0
+    this.classes.filter { it.type.endsWith("$targetClass;") }.forEach { classDef ->
+        this.proxy(classDef).resolve().methods.filter { it.name == targetMethod }.forEach { methodDef ->
+            // if index is negative, interpret as an offset from the back
+            var insertIndex = index
+            if (insertIndex < 0) {
+                insertIndex += methodDef.implementation!!.instructions.size
+            }
+
+            // insert instructions
+            methodDef.addInstructions(insertIndex, instructions)
+            injections++
+        }
+    }
+
+    // fail if nothing was injected
+    if (injections <= 0) {
+        throw PatchResultError("failed to inject into $targetClass.$targetMethod: no targets were found")
+    }
+}
+
 internal fun Node.doRecursively(action: (Node) -> Unit) {
     action(this)
     for (i in 0 until this.childNodes.length) this.childNodes.item(i).doRecursively(action)