From dcdedf5b1ae6c3d4eeeb9fdfa7c88fb75c4c4fbd Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Mon, 2 Sep 2024 14:46:32 +0200
Subject: [PATCH] undo: have a single delta for both undo and redo

---
 include/clap/ext/draft/undo.h | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/include/clap/ext/draft/undo.h b/include/clap/ext/draft/undo.h
index 365780e6..4cfa17ff 100644
--- a/include/clap/ext/draft/undo.h
+++ b/include/clap/ext/draft/undo.h
@@ -76,14 +76,23 @@ typedef struct clap_plugin_undo {
    bool(CLAP_ABI *can_use_delta_format_version)(const clap_plugin_t *plugin,
                                                 clap_id              format_version);
 
-   // Applies synchronously a delta.
+   // Undo using the delta.
    // Returns true on success.
    //
    // [main-thread]
-   bool(CLAP_ABI *apply_delta)(const clap_plugin_t *plugin,
-                               clap_id              format_version,
-                               const void          *delta,
-                               size_t               delta_size);
+   bool(CLAP_ABI *undo)(const clap_plugin_t *plugin,
+                        clap_id              format_version,
+                        const void          *delta,
+                        size_t               delta_size);
+
+   // Redo using the delta.
+   // Returns true on success.
+   //
+   // [main-thread]
+   bool(CLAP_ABI *redo)(const clap_plugin_t *plugin,
+                        clap_id              format_version,
+                        const void          *delta,
+                        size_t               delta_size);
 
    // Sets the undo context.
    // flags: bitmask of clap_undo_context_flags values
@@ -112,7 +121,7 @@ typedef struct clap_host_undo {
    //
    // name: mandatory null terminated string describing the change, this is displayed to the user
    //
-   // deltas: optional, they are binary blobs used to perform the undo and redo. When not available
+   // delta: optional, it is a binary blobs used to perform the undo and redo. When not available
    // the host will save the plugin state and use state->load() to perform undo and redo.
    //
    // Note: the provided delta may be used for incremental state saving and crash recovery. The
@@ -128,18 +137,16 @@ typedef struct clap_host_undo {
    // [main-thread]
    void(CLAP_ABI *change_made)(const clap_host_t *host,
                                const char        *name,
-                               const void        *redo_delta,
-                               size_t             redo_delta_size,
-                               const void        *undo_delta,
-                               size_t             undo_delta_size);
+                               const void        *delta,
+                               size_t             delta_size);
 
    // Asks the host to perform the next undo step.
-   // This operation may be asynchronous.
+   // This operation may be asynchronous and isn't available while the host is within a change.
    // [main-thread]
    void(CLAP_ABI *undo)(const clap_host_t *host);
 
    // Asks the host to perform the next redo step.
-   // This operation may be asynchronous.
+   // This operation may be asynchronous and isn't available while the host is within a change.
    // [main-thread]
    void(CLAP_ABI *redo)(const clap_host_t *host);