From 0f814eb13408a3696bccacc6cac0e65fece9df04 Mon Sep 17 00:00:00 2001
From: ml <krotik@devt.de>
Date: Sun, 14 Jun 2026 10:04:59 +0200
Subject: [PATCH] Adding a save state panel

---
 .../C64Engine.kt                              |   6 +
 .../MainActivity.kt                           | 107 ++++++++++++++++++
 .../app/src/main/jni/CMakeLists.txt           |   4 +-
 .../app/src/main/jni/vice_jni.c               |  88 ++++++++++++--
 .../app/src/main/res/layout/activity_main.xml |  11 ++
 .../app/src/main/res/values-de/strings.xml    |   7 ++
 .../app/src/main/res/values/strings.xml       |   7 ++
 7 files changed, 221 insertions(+), 9 deletions(-)

diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/C64Engine.kt b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/C64Engine.kt
index 98952f0..97b5502 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/C64Engine.kt
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/C64Engine.kt
@@ -28,6 +28,12 @@ class C64Engine {
     /** Eject the disk and hard-reset the C64 to a BASIC ready prompt. */
     external fun resetMachine(): Boolean
 
+    /** Save a full machine snapshot to [path] (queued to the VICE thread). */
+    external fun saveState(path: String): Boolean
+
+    /** Restore a machine snapshot from [path] (queued to the VICE thread). */
+    external fun loadState(path: String): Boolean
+
     /** Run the emulator for one video frame (~20 000 CPU cycles). */
     external fun runFrame()
 
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/MainActivity.kt b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/MainActivity.kt
index 326f3c0..4b0c816 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/MainActivity.kt
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/java/de/ladkau/schwertundmagieonpebblecompanionapp/MainActivity.kt
@@ -170,6 +170,7 @@ class MainActivity : AppCompatActivity() {
         }
 
         findViewById<Button>(R.id.btn_help).setOnClickListener { showHelp() }
+        findViewById<Button>(R.id.btn_savestate).setOnClickListener { showSaveStatePanel() }
 
         findViewById<Button>(R.id.btn_import_disks).setOnClickListener {
             launchPicker(diskPickerLauncher, getString(R.string.picker_title), multiSelect = true)
@@ -660,6 +661,112 @@ class MainActivity : AppCompatActivity() {
 
     // ---- helpers ------------------------------------------------------------
 
+    // ---- save state panel ---------------------------------------------------
+
+    private fun stateFile(slot: Int): File {
+        val dir = getExternalFilesDir(null) ?: filesDir
+        return File(dir, "SAVESTATE_$slot.VSF")
+    }
+
+    private fun showSaveStatePanel() {
+        val dp     = { v: Int -> (v * resources.displayMetrics.density).toInt() }
+        val dateFmt = SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.getDefault())
+
+        val content = android.widget.LinearLayout(this).apply {
+            orientation = android.widget.LinearLayout.VERTICAL
+            setPadding(dp(16), dp(12), dp(16), dp(8))
+            setBackgroundColor(Color.parseColor("#1A1A2E"))
+        }
+
+        // Per-slot views that need refreshing after a Save
+        val timeTvs   = arrayOfNulls<TextView>(5)
+        val loadBtns  = arrayOfNulls<Button>(5)
+        var dialog: AlertDialog? = null
+
+        for (slot in 1..5) {
+            val file   = stateFile(slot)
+            val idx    = slot - 1
+
+            val row = android.widget.LinearLayout(this).apply {
+                orientation = android.widget.LinearLayout.HORIZONTAL
+                gravity = android.view.Gravity.CENTER_VERTICAL
+                layoutParams = android.widget.LinearLayout.LayoutParams(
+                    android.widget.LinearLayout.LayoutParams.MATCH_PARENT,
+                    android.widget.LinearLayout.LayoutParams.WRAP_CONTENT
+                ).apply { bottomMargin = dp(6) }
+            }
+
+            row.addView(TextView(this).apply {
+                text = getString(R.string.savestate_slot, slot)
+                textSize = 12f
+                setTextColor(Color.parseColor("#AAFFAA"))
+                layoutParams = android.widget.LinearLayout.LayoutParams(dp(52),
+                    android.widget.LinearLayout.LayoutParams.WRAP_CONTENT)
+            })
+
+            val timeTv = TextView(this).apply {
+                val exists = file.exists()
+                text = if (exists) dateFmt.format(Date(file.lastModified()))
+                       else getString(R.string.savestate_empty)
+                textSize = 11f
+                setTextColor(if (exists) Color.parseColor("#AAAAAA") else Color.parseColor("#444444"))
+                layoutParams = android.widget.LinearLayout.LayoutParams(0,
+                    android.widget.LinearLayout.LayoutParams.WRAP_CONTENT, 1f)
+            }
+            timeTvs[idx] = timeTv
+            row.addView(timeTv)
+
+            val loadBtn = Button(this).apply {
+                text = getString(R.string.savestate_load)
+                textSize = 11f
+                isEnabled = file.exists()
+                layoutParams = android.widget.LinearLayout.LayoutParams(dp(80),
+                    android.widget.LinearLayout.LayoutParams.WRAP_CONTENT).apply {
+                    marginStart = dp(4)
+                }
+                setOnClickListener {
+                    engine.loadState(file.absolutePath)
+                    appendLog("State loaded: slot $slot")
+                    dialog?.dismiss()
+                }
+            }
+            loadBtns[idx] = loadBtn
+            row.addView(loadBtn)
+
+            row.addView(Button(this).apply {
+                text = getString(R.string.savestate_save)
+                textSize = 11f
+                layoutParams = android.widget.LinearLayout.LayoutParams(dp(80),
+                    android.widget.LinearLayout.LayoutParams.WRAP_CONTENT).apply {
+                    marginStart = dp(4)
+                }
+                setOnClickListener {
+                    engine.saveState(file.absolutePath)
+                    appendLog("State saved: slot $slot")
+                    // VICE writes asynchronously; refresh the row after one second
+                    mainHandler.postDelayed({
+                        if (file.exists()) {
+                            timeTvs[idx]?.text = dateFmt.format(Date(file.lastModified()))
+                            timeTvs[idx]?.setTextColor(Color.parseColor("#AAAAAA"))
+                            loadBtns[idx]?.isEnabled = true
+                        }
+                    }, 1000)
+                }
+            })
+
+            content.addView(row)
+        }
+
+        dialog = AlertDialog.Builder(this)
+            .setTitle(R.string.savestate_title)
+            .setView(android.widget.ScrollView(this).apply {
+                addView(content)
+                setBackgroundColor(Color.parseColor("#1A1A2E"))
+            })
+            .setNegativeButton(R.string.cancel, null)
+            .show()
+    }
+
     private fun showHelp() {
         fun load(german: Boolean) = try {
             assets.open(if (german) "help_de.md" else "help_en.md").bufferedReader().readText()
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/CMakeLists.txt b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/CMakeLists.txt
index b0fd84d..306bc8d 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/CMakeLists.txt
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/CMakeLists.txt
@@ -30,7 +30,9 @@ if(HAVE_VICE)
         -Wl,--wrap=machine_init
         -Wl,--wrap=console_init
         -Wl,--wrap=ui_display_drive_led
-        -Wl,--wrap=serial_trap_receive)
+        -Wl,--wrap=serial_trap_receive
+        -Wl,--wrap=event_snapshot_write_module
+        -Wl,--wrap=event_snapshot_read_module)
     target_include_directories(vice_jni PRIVATE
         "${CMAKE_CURRENT_SOURCE_DIR}/vice-libs/${ANDROID_ABI}"
         "${VICE_SRC}/src"
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/vice_jni.c b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/vice_jni.c
index 5af587e..3a12486 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/vice_jni.c
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/jni/vice_jni.c
@@ -36,16 +36,20 @@ static uint32_t        g_framebuf[FRAME_W * FRAME_H];
 static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
 static int             g_ready = 0;
 
-/* Pending disk/reset operations — written by Android thread, consumed by
- * video_canvas_refresh on the VICE thread (machine_trigger_reset and disk APIs
- * must be called from the VICE thread to avoid corrupting internal state).
- * g_pending_disk   → autostart_disk (resets the machine, used for A-side disks)
- * g_pending_attach → file_system_attach_disk (hot-swap, used for B-side / hero disks)
- * g_pending_reset  → detach disk + hard reset to BASIC prompt */
-static pthread_mutex_t g_pending_lock   = PTHREAD_MUTEX_INITIALIZER;
+/* Pending disk/reset/snapshot operations — written by Android thread, consumed by
+ * video_canvas_refresh on the VICE thread (machine_trigger_reset, disk APIs, and
+ * snapshot APIs must be called from the VICE thread to avoid corrupting state).
+ * g_pending_disk       → autostart_disk (resets machine, used for A-side disks)
+ * g_pending_attach     → file_system_attach_disk (hot-swap, B-side / hero disks)
+ * g_pending_reset      → detach disk + hard reset to BASIC prompt
+ * g_pending_save_state → machine_write_snapshot (save full machine state)
+ * g_pending_load_state → machine_read_snapshot  (restore full machine state) */
+static pthread_mutex_t g_pending_lock       = PTHREAD_MUTEX_INITIALIZER;
 static char            g_pending_disk[512];
 static char            g_pending_attach[512];
-static volatile int    g_pending_reset  = 0;
+static volatile int    g_pending_reset      = 0;
+static char            g_pending_save_state[512];
+static char            g_pending_load_state[512];
 
 /* =========================================================================
  * VICE integration (compiled only when libvice.a is linked in)
@@ -278,6 +282,20 @@ static const sound_device_t g_android_sound_device = {
 /* Stubs for symbols that live in arch-specific or excluded files. */
 void main_exit(void) {}
 
+/* event_snapshot_write/read_module: VICE's event-recording system allocates its
+ * history buffer (start_snapshot.list.base) only when recording is explicitly
+ * started via event_record_start().  In our headless build recording is never
+ * started, so the buffer stays NULL and the real implementations crash with a
+ * null-pointer dereference when called from machine_write_snapshot.
+ * Replace them with no-ops: snapshots work fine without event playback data. */
+struct snapshot_s;
+int __wrap_event_snapshot_write_module(struct snapshot_s *s, int event_mode) {
+    (void)s; (void)event_mode; return 0;
+}
+int __wrap_event_snapshot_read_module(struct snapshot_s *s) {
+    (void)s; return 0;
+}
+
 /* All functions below replace arch/headless/video.c (excluded from libvice.a). */
 
 int  video_arch_get_active_chip(void)              { return 0; /* VIDEO_CHIP_VICII */ }
@@ -384,6 +402,28 @@ void video_canvas_refresh(video_canvas_t *canvas,
         }
     }
 
+    /* Snapshot save / load. */
+    pthread_mutex_lock(&g_pending_lock);
+    char save_state_path[512] = {0};
+    char load_state_path[512] = {0};
+    if (g_pending_save_state[0] != '\0') {
+        strncpy(save_state_path, g_pending_save_state, sizeof(save_state_path) - 1);
+        g_pending_save_state[0] = '\0';
+    }
+    if (g_pending_load_state[0] != '\0') {
+        strncpy(load_state_path, g_pending_load_state, sizeof(load_state_path) - 1);
+        g_pending_load_state[0] = '\0';
+    }
+    pthread_mutex_unlock(&g_pending_lock);
+    if (save_state_path[0] != '\0') {
+        int r = machine_write_snapshot(save_state_path, 0, 1, 1);
+        LOGI("machine_write_snapshot → %d", r);
+    }
+    if (load_state_path[0] != '\0') {
+        int r = machine_read_snapshot(load_state_path, 0);
+        LOGI("machine_read_snapshot → %d", r);
+    }
+
     /* Drive LED.
      * VICE's virtual device (vdrive) loads far faster than a real 1541, so
      * autostart_in_progress() is false long before the GDG intro finishes.
@@ -717,3 +757,35 @@ JNI_FN(void, setSoundEnabled)(JNIEnv *env, jobject obj, jboolean enabled) {
     (void)env; (void)obj;
     g_sound_enabled = enabled ? 1 : 0;
 }
+
+JNI_FN(jboolean, saveState)(JNIEnv *env, jobject obj, jstring jpath) {
+    (void)obj;
+#ifdef HAVE_VICE_SRC
+    const char *p = (*env)->GetStringUTFChars(env, jpath, NULL);
+    pthread_mutex_lock(&g_pending_lock);
+    strncpy(g_pending_save_state, p, sizeof(g_pending_save_state) - 1);
+    g_pending_save_state[sizeof(g_pending_save_state) - 1] = '\0';
+    pthread_mutex_unlock(&g_pending_lock);
+    (*env)->ReleaseStringUTFChars(env, jpath, p);
+    return JNI_TRUE;
+#else
+    (void)env; (void)jpath;
+    return JNI_FALSE;
+#endif
+}
+
+JNI_FN(jboolean, loadState)(JNIEnv *env, jobject obj, jstring jpath) {
+    (void)obj;
+#ifdef HAVE_VICE_SRC
+    const char *p = (*env)->GetStringUTFChars(env, jpath, NULL);
+    pthread_mutex_lock(&g_pending_lock);
+    strncpy(g_pending_load_state, p, sizeof(g_pending_load_state) - 1);
+    g_pending_load_state[sizeof(g_pending_load_state) - 1] = '\0';
+    pthread_mutex_unlock(&g_pending_lock);
+    (*env)->ReleaseStringUTFChars(env, jpath, p);
+    return JNI_TRUE;
+#else
+    (void)env; (void)jpath;
+    return JNI_FALSE;
+#endif
+}
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/layout/activity_main.xml b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/layout/activity_main.xml
index 9b37a61..8cf3c72 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/layout/activity_main.xml
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/layout/activity_main.xml
@@ -51,6 +51,17 @@
                 android:layout_height="12dp"
                 android:layout_marginEnd="4dp" />
 
+            <Button
+                android:id="@+id/btn_savestate"
+                style="?attr/materialButtonOutlinedStyle"
+                android:layout_width="36dp"
+                android:layout_height="36dp"
+                android:layout_marginEnd="4dp"
+                android:minWidth="0dp"
+                android:padding="0dp"
+                android:text="💾"
+                android:textSize="16sp" />
+
             <Button
                 android:id="@+id/btn_help"
                 style="?attr/materialButtonOutlinedStyle"
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values-de/strings.xml b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values-de/strings.xml
index 88b6714..b8a1f1d 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values-de/strings.xml
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values-de/strings.xml
@@ -30,6 +30,13 @@
     <string name="hero_disk_created">Erstellt: %1$s</string>
     <string name="hero_disk_create_failed">Fehler beim Erstellen: %1$s</string>
 
+    <!-- Save state panel -->
+    <string name="savestate_title">Spielstände</string>
+    <string name="savestate_slot">Slot %1$d</string>
+    <string name="savestate_empty">leer</string>
+    <string name="savestate_save">Speichern</string>
+    <string name="savestate_load">Laden</string>
+
     <!-- Hero save editor -->
     <string name="editor_title">%1$s bearbeiten</string>
     <string name="editor_save">Speichern</string>
diff --git a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values/strings.xml b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values/strings.xml
index 861d34c..7258753 100644
--- a/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values/strings.xml
+++ b/SchwertUndMagieOnPebbleCompanionApp/app/src/main/res/values/strings.xml
@@ -32,6 +32,13 @@
     <string name="hero_disk_created">Created: %1$s</string>
     <string name="hero_disk_create_failed">Failed to create: %1$s</string>
 
+    <!-- Save state panel -->
+    <string name="savestate_title">Save States</string>
+    <string name="savestate_slot">Slot %1$d</string>
+    <string name="savestate_empty">empty</string>
+    <string name="savestate_save">Save</string>
+    <string name="savestate_load">Load</string>
+
     <!-- Hero save editor -->
     <string name="editor_title">Edit %1$s</string>
     <string name="editor_save">Save</string>