From 7c1931ebb066fc849ce32d47ab15b33b628a6b9a Mon Sep 17 00:00:00 2001
From: Allen Webster <editor@4coder.net>
Date: Sun, 3 May 2020 06:24:39 -0700
Subject: [PATCH] View change buffer hook

---
 4ed_api_implementation.cpp      | 8 ++++++++
 4ed_app_models.h                | 1 +
 4ed_view.cpp                    | 7 +++++++
 custom/4coder_default_hooks.cpp | 6 ++++++
 custom/4coder_types.h           | 4 ++++
 5 files changed, 26 insertions(+)

diff --git a/4ed_api_implementation.cpp b/4ed_api_implementation.cpp
index 50787a52..7e6f218f 100644
--- a/4ed_api_implementation.cpp
+++ b/4ed_api_implementation.cpp
@@ -2218,6 +2218,10 @@ set_custom_hook(Application_Links *app, Hook_ID hook_id, Void_Func *func_ptr){
         {
             models->layout_func = (Layout_Function*)func_ptr;
         }break;
+        case HookID_ViewChangeBuffer:
+        {
+            models->view_change_buffer = (View_Change_Buffer_Function*)func_ptr;
+        }break;
     }
 }
 
@@ -2282,6 +2286,10 @@ get_custom_hook(Application_Links *app, Hook_ID hook_id){
         {
             result = (Void_Func*)models->layout_func;
         }break;
+        case HookID_ViewChangeBuffer:
+        {
+            result = (Void_Func*)models->view_change_buffer;
+        }break;
     }
     return(result);
 }
diff --git a/4ed_app_models.h b/4ed_app_models.h
index d8ad515a..594c7d65 100644
--- a/4ed_app_models.h
+++ b/4ed_app_models.h
@@ -82,6 +82,7 @@ struct Models{
     Buffer_Edit_Range_Function *buffer_edit_range;
     Buffer_Region_Function *buffer_region;
     Layout_Function *layout_func;
+    View_Change_Buffer_Function *view_change_buffer;
     
     Color_Table color_table_;
     
diff --git a/4ed_view.cpp b/4ed_view.cpp
index fb54ce8e..93ebe3bd 100644
--- a/4ed_view.cpp
+++ b/4ed_view.cpp
@@ -447,6 +447,13 @@ internal void
 view_set_file(Thread_Context *tctx, Models *models, View *view, Editing_File *file){
     Assert(file != 0);
     
+    if (models->view_change_buffer != 0){
+        Application_Links app = {};
+        app.tctx = tctx;
+        app.cmd_context = models;
+        models->view_change_buffer(&app, view_get_id(&models->view_set, view), file->id);
+    }
+    
     Editing_File *old_file = view->file;
     if (old_file != 0){
         file_touch(&models->working_set, old_file);
diff --git a/custom/4coder_default_hooks.cpp b/custom/4coder_default_hooks.cpp
index c3670845..8561095e 100644
--- a/custom/4coder_default_hooks.cpp
+++ b/custom/4coder_default_hooks.cpp
@@ -1038,6 +1038,11 @@ BUFFER_HOOK_SIG(default_end_buffer){
     return(0);
 }
 
+function void
+default_view_change_buffer(Application_Links *app, View_ID view_id, Buffer_ID buffer_id){
+    // do nothing
+}
+
 internal void
 set_all_default_hooks(Application_Links *app){
     set_custom_hook(app, HookID_BufferViewerUpdate, default_view_adjust);
@@ -1059,6 +1064,7 @@ set_all_default_hooks(Application_Links *app){
     set_custom_hook(app, HookID_SaveFile, default_file_save);
     set_custom_hook(app, HookID_BufferEditRange, default_buffer_edit_range);
     set_custom_hook(app, HookID_BufferRegion, default_buffer_region);
+    set_custom_hook(app, HookID_ViewChangeBuffer, default_view_change_buffer);
     
     set_custom_hook(app, HookID_Layout, layout_unwrapped);
     //set_custom_hook(app, HookID_Layout, layout_wrap_anywhere);
diff --git a/custom/4coder_types.h b/custom/4coder_types.h
index 42affdad..d74e3d98 100644
--- a/custom/4coder_types.h
+++ b/custom/4coder_types.h
@@ -650,6 +650,7 @@ enum{
     HookID_BufferEditRange,
     HookID_BufferRegion,
     HookID_Layout,
+    HookID_ViewChangeBuffer,
 };
 
 api(custom)
@@ -699,6 +700,9 @@ typedef void Render_Caller_Function(Application_Links *app, Frame_Info frame_inf
 api(custom)
 typedef void Whole_Screen_Render_Caller_Function(Application_Links *app, Frame_Info frame_info);
 
+api(custom)
+typedef void View_Change_Buffer_Function(Application_Links *app, View_ID view_id, Buffer_ID buffer_id);
+
 api(custom)
 typedef u32 Layout_Item_Flag;
 enum{