From fedd2057a22c767792be1d51d3eabac83824a5a0 Mon Sep 17 00:00:00 2001
From: Harry Jeffery <harry@exec64.co.uk>
Date: Fri, 24 Nov 2017 16:55:53 +0000
Subject: loader: Use event to pass image loading error to main thread

---
 src/imv.c    | 38 ++++++++++++++++++++------------------
 src/loader.c | 30 +++++++++++-------------------
 src/loader.h | 11 ++++-------
 3 files changed, 35 insertions(+), 44 deletions(-)

(limited to 'src')

diff --git a/src/imv.c b/src/imv.c
index 5484c89..a89f97f 100644
--- a/src/imv.c
+++ b/src/imv.c
@@ -95,6 +95,7 @@ struct imv {
   bool ttf_init;
   struct {
     unsigned int NEW_IMAGE;
+    unsigned int BAD_IMAGE;
   } events;
   struct {
     int width;
@@ -495,23 +496,6 @@ int imv_run(struct imv *imv)
       break;
     }
 
-    /* check if an image failed to load, if so, remove it from our image list */
-    char *err_path = imv_loader_get_error(imv->loader);
-    if(err_path) {
-      imv_navigator_remove(imv->navigator, err_path);
-
-      /* special case: the image came from stdin */
-      if(strcmp(err_path, "-") == 0) {
-        if(imv->stdin_image_data) {
-          free(imv->stdin_image_data);
-          imv->stdin_image_data = NULL;
-          imv->stdin_image_data_len = 0;
-        }
-        fprintf(stderr, "Failed to load image from stdin.\n");
-      }
-      free(err_path);
-    }
-
     /* Check if navigator wrapped around paths lists */
     if(!imv->cycle_input && imv_navigator_wrapped(imv->navigator)) {
       break;
@@ -631,9 +615,12 @@ static bool setup_window(struct imv *imv)
 
   /* register custom events */
   imv->events.NEW_IMAGE = SDL_RegisterEvents(1);
+  imv->events.BAD_IMAGE = SDL_RegisterEvents(1);
 
   /* tell the loader which event ids it should use */
-  imv_loader_set_event_types(imv->loader, imv->events.NEW_IMAGE);
+  imv_loader_set_event_types(imv->loader,
+      imv->events.NEW_IMAGE,
+      imv->events.BAD_IMAGE);
 
   imv->sdl_init = true;
 
@@ -707,6 +694,21 @@ static void handle_event(struct imv *imv, SDL_Event *event)
     imv->need_redraw = true;
     imv->need_rescale |= event->user.code;
     return;
+  } else if(event->type == imv->events.BAD_IMAGE) {
+    /* an image failed to load, remove it from our image list */
+    char *err_path = event->user.data1;
+    imv_navigator_remove(imv->navigator, err_path);
+
+    /* special case: the image came from stdin */
+    if(strcmp(err_path, "-") == 0) {
+      if(imv->stdin_image_data) {
+        free(imv->stdin_image_data);
+        imv->stdin_image_data = NULL;
+        imv->stdin_image_data_len = 0;
+      }
+      fprintf(stderr, "Failed to load image from stdin.\n");
+    }
+    free(err_path);
   }
 
   switch(event->type) {
diff --git a/src/loader.c b/src/loader.c
index cbebf2c..2a3a08c 100644
--- a/src/loader.c
+++ b/src/loader.c
@@ -101,23 +101,12 @@ void imv_loader_load(struct imv_loader *ldr, const char *path,
   pthread_mutex_unlock(&ldr->lock);
 }
 
-void imv_loader_set_event_types(struct imv_loader *ldr, unsigned int new_image)
+void imv_loader_set_event_types(struct imv_loader *ldr,
+    unsigned int new_image,
+    unsigned int bad_image)
 {
   ldr->new_image_event = new_image;
-}
-
-char *imv_loader_get_error(struct imv_loader *ldr)
-{
-  char *err = NULL;
-  pthread_mutex_lock(&ldr->lock);
-
-  if(ldr->out_err) {
-    err = ldr->out_err;
-    ldr->out_err = NULL;
-  }
-
-  pthread_mutex_unlock(&ldr->lock);
-  return err;
+  ldr->bad_image_event = bad_image;
 }
 
 void imv_loader_load_next_frame(struct imv_loader *ldr)
@@ -418,11 +407,14 @@ static void *bg_next_frame(void *data)
 static void error_occurred(struct imv_loader *ldr)
 {
   pthread_mutex_lock(&ldr->lock);
-  if(ldr->out_err) {
-    free(ldr->out_err);
-  }
-  ldr->out_err = strdup(ldr->path);
+  char *err_path = strdup(ldr->path);
   pthread_mutex_unlock(&ldr->lock);
+
+  SDL_Event event;
+  SDL_zero(event);
+  event.type = ldr->bad_image_event;
+  event.user.data1 = err_path;
+  SDL_PushEvent(&event);
 }
 
 
diff --git a/src/loader.h b/src/loader.h
index 07fe068..197b6e2 100644
--- a/src/loader.h
+++ b/src/loader.h
@@ -31,7 +31,6 @@ struct imv_loader {
   BYTE *buffer;
   size_t buffer_size;
   FIMEMORY *fi_buffer;
-  char *out_err;
   FIMULTIBITMAP *mbmp;
   FIBITMAP *bmp;
   int width;
@@ -41,6 +40,7 @@ struct imv_loader {
   int num_frames;
   double frame_time;
   unsigned int new_image_event;
+  unsigned int bad_image_event;
 };
 
 /* Creates an instance of imv_loader */
@@ -54,12 +54,9 @@ void imv_loader_load(struct imv_loader *ldr, const char *path,
                      const void *buffer, const size_t buffer_size);
 
 /* Set the custom event types for returning data */
-void imv_loader_set_event_types(struct imv_loader *ldr, unsigned int new_image);
-
-/* If a file failed to load, return the path to that file. Otherwise returns
- * NULL. Only returns the path once. Caller is responsible for cleaning up the
- * string returned. */
-char *imv_loader_get_error(struct imv_loader *ldr);
+void imv_loader_set_event_types(struct imv_loader *ldr,
+    unsigned int new_image,
+    unsigned int bad_image);
 
 /* Trigger the next frame of the currently loaded image to be loaded and
  * returned as soon as possible. */
-- 
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