Cleanup: Reduce variable scope in node drawing code

Also use LISTBASE_FOREACH in a few places and generally clean up
the code for the two sidebar panels "Sockets" and "Interface".

2 files changed, 110 insertions, 130 deletions

diff --git a/source/blender/editors/space_node/node_buttons.c b/source/blender/editors/space_node/node_buttons.c
index 6475e753409..0aba45ceafc 100644
--- a/source/blender/editors/space_node/node_buttons.c
+++ b/source/blender/editors/space_node/node_buttons.c
@@ -68,23 +68,20 @@ static bool node_sockets_poll(const bContext *C, PanelType *UNUSED(pt))
 
 static void node_sockets_panel(const bContext *C, Panel *panel)
 {
-  SpaceNode *snode = CTX_wm_space_node(C);
-  bNodeTree *ntree = (snode) ? snode->edittree : NULL;
-  bNode *node = (ntree) ? nodeGetActive(ntree) : NULL;
-  bNodeSocket *sock;
-  uiLayout *layout = panel->layout, *split;
-  char name[UI_MAX_NAME_STR];
-
-  if (ELEM(NULL, ntree, node)) {
+  SpaceNode *snode = CTX_wm_space_node(C); /* NULL checked in poll function. */
+  bNodeTree *ntree = snode->edittree;      /* NULL checked in poll function. */
+  bNode *node = nodeGetActive(ntree);
+  if (node == NULL) {
     return;
   }
 
-  for (sock = node->inputs.first; sock; sock = sock->next) {
-    BLI_snprintf(name, sizeof(name), "%s:", sock->name);
+  LISTBASE_FOREACH (bNodeSocket *, socket, &node->inputs) {
+    char name[UI_MAX_NAME_STR];
+    BLI_snprintf(name, sizeof(name), "%s:", socket->name);
 
-    split = uiLayoutSplit(layout, 0.35f, false);
+    uiLayout *split = uiLayoutSplit(panel->layout, 0.35f, false);
     uiItemL(split, name, ICON_NONE);
-    uiTemplateNodeLink(split, (bContext *)C, ntree, node, sock);
+    uiTemplateNodeLink(split, (bContext *)C, ntree, node, socket);
   }
 }
 
@@ -96,19 +93,20 @@ static bool node_tree_interface_poll(const bContext *C, PanelType *UNUSED(pt))
           (snode->edittree->inputs.first || snode->edittree->outputs.first));
 }
 
-static bool node_tree_find_active_socket(bNodeTree *ntree, bNodeSocket **r_sock, int *r_in_out)
+static bool node_tree_find_active_socket(bNodeTree *ntree,
+                                         bNodeSocket **r_sock,
+                                         eNodeSocketInOut *r_in_out)
 {
-  bNodeSocket *sock;
-  for (sock = ntree->inputs.first; sock; sock = sock->next) {
-    if (sock->flag & SELECT) {
-      *r_sock = sock;
+  LISTBASE_FOREACH (bNodeSocket *, socket, &ntree->inputs) {
+    if (socket->flag & SELECT) {
+      *r_sock = socket;
       *r_in_out = SOCK_IN;
       return true;
     }
   }
-  for (sock = ntree->outputs.first; sock; sock = sock->next) {
-    if (sock->flag & SELECT) {
-      *r_sock = sock;
+  LISTBASE_FOREACH (bNodeSocket *, socket, &ntree->outputs) {
+    if (socket->flag & SELECT) {
+      *r_sock = socket;
       *r_in_out = SOCK_OUT;
       return true;
     }
@@ -121,28 +119,24 @@ static bool node_tree_find_active_socket(bNodeTree *ntree, bNodeSocket **r_sock,
 
 static void node_tree_interface_panel(const bContext *C, Panel *panel)
 {
-  SpaceNode *snode = CTX_wm_space_node(C);
-  bNodeTree *ntree = (snode) ? snode->edittree : NULL;
-  bNodeSocket *sock;
-  int in_out;
-  uiLayout *layout = panel->layout, *row, *split, *col;
-  PointerRNA ptr, sockptr, opptr;
-  wmOperatorType *ot;
-
-  if (!ntree) {
-    return;
-  }
+  SpaceNode *snode = CTX_wm_space_node(C); /* NULL checked in poll function. */
+  bNodeTree *ntree = snode->edittree;      /* NULL checked in poll function. */
+  uiLayout *layout = panel->layout;
 
+  PointerRNA ptr;
   RNA_id_pointer_create((ID *)ntree, &ptr);
 
-  node_tree_find_active_socket(ntree, &sock, &in_out);
-  RNA_pointer_create((ID *)ntree, &RNA_NodeSocketInterface, sock, &sockptr);
+  bNodeSocket *socket;
+  eNodeSocketInOut in_out;
+  node_tree_find_active_socket(ntree, &socket, &in_out);
+  PointerRNA sockptr;
+  RNA_pointer_create((ID *)ntree, &RNA_NodeSocketInterface, socket, &sockptr);
 
-  row = uiLayoutRow(layout, false);
+  uiLayout *row = uiLayoutRow(layout, false);
 
-  split = uiLayoutRow(row, true);
-  col = uiLayoutColumn(split, true);
-  ot = WM_operatortype_find("NODE_OT_tree_socket_add", false);
+  uiLayout *split = uiLayoutRow(row, true);
+  uiLayout *col = uiLayoutColumn(split, true);
+  wmOperatorType *ot = WM_operatortype_find("NODE_OT_tree_socket_add", false);
   uiItemL(col, IFACE_("Inputs:"), ICON_NONE);
   uiTemplateList(col,
                  (bContext *)C,
@@ -159,6 +153,7 @@ static void node_tree_interface_panel(const bContext *C, Panel *panel)
                  0,
                  false,
                  false);
+  PointerRNA opptr;
   uiItemFullO_ptr(col, ot, "", ICON_PLUS, NULL, WM_OP_EXEC_DEFAULT, 0, &opptr);
   RNA_enum_set(&opptr, "in_out", SOCK_IN);
 
@@ -189,14 +184,14 @@ static void node_tree_interface_panel(const bContext *C, Panel *panel)
   uiItemFullO_ptr(col, ot, "", ICON_TRIA_DOWN, NULL, WM_OP_EXEC_DEFAULT, 0, &opptr);
   RNA_enum_set(&opptr, "direction", 2);
 
-  if (sock) {
+  if (socket) {
     row = uiLayoutRow(layout, true);
     uiItemR(row, &sockptr, "name", 0, NULL, ICON_NONE);
     uiItemO(row, "", ICON_X, "NODE_OT_tree_socket_remove");
 
-    if (sock->typeinfo->interface_draw) {
+    if (socket->typeinfo->interface_draw) {
       uiItemS(layout);
-      sock->typeinfo->interface_draw((bContext *)C, layout, &sockptr);
+      socket->typeinfo->interface_draw((bContext *)C, layout, &sockptr);
     }
   }
 }
diff --git a/source/blender/editors/space_node/node_draw.c b/source/blender/editors/space_node/node_draw.c
index 0e68ebe7c03..a567ae41a54 100644
--- a/source/blender/editors/space_node/node_draw.c
+++ b/source/blender/editors/space_node/node_draw.c
@@ -300,7 +300,6 @@ static void do_node_internal_buttons(bContext *C, void *UNUSED(node_v), int even
 
 static void node_uiblocks_init(const bContext *C, bNodeTree *ntree)
 {
-
   /* add node uiBlocks in drawing order - prevents events going to overlapping nodes */
 
   LISTBASE_FOREACH (bNode *, node, &ntree->nodes) {
@@ -995,8 +994,7 @@ void node_draw_sockets(View2D *v2d,
 
   /* socket inputs */
   short selected_input_len = 0;
-  bNodeSocket *sock;
-  for (sock = node->inputs.first; sock; sock = sock->next) {
+  LISTBASE_FOREACH (bNodeSocket *, sock, &node->inputs) {
     if (nodeSocketIsHidden(sock)) {
       continue;
     }
@@ -1021,7 +1019,7 @@ void node_draw_sockets(View2D *v2d,
   /* socket outputs */
   short selected_output_len = 0;
   if (draw_outputs) {
-    for (sock = node->outputs.first; sock; sock = sock->next) {
+    LISTBASE_FOREACH (bNodeSocket *, sock, &node->outputs) {
       if (nodeSocketIsHidden(sock)) {
         continue;
       }
@@ -1058,7 +1056,7 @@ void node_draw_sockets(View2D *v2d,
 
     if (selected_input_len) {
       /* socket inputs */
-      for (sock = node->inputs.first; sock; sock = sock->next) {
+      LISTBASE_FOREACH (bNodeSocket *, sock, &node->inputs) {
         if (nodeSocketIsHidden(sock)) {
           continue;
         }
@@ -1083,7 +1081,7 @@ void node_draw_sockets(View2D *v2d,
 
     if (selected_output_len) {
       /* socket outputs */
-      for (sock = node->outputs.first; sock; sock = sock->next) {
+      LISTBASE_FOREACH (bNodeSocket *, sock, &node->outputs) {
         if (nodeSocketIsHidden(sock)) {
           continue;
         }
@@ -1162,23 +1160,22 @@ static void node_draw_basis(const bContext *C,
 
   /* preview */
   if (node->typeinfo->flag & NODE_PREVIEW) {
-    uiBut *but;
     iconofs -= iconbutw;
     UI_block_emboss_set(node->block, UI_EMBOSS_NONE);
-    but = uiDefIconBut(node->block,
-                       UI_BTYPE_BUT_TOGGLE,
-                       B_REDR,
-                       ICON_MATERIAL,
-                       iconofs,
-                       rct->ymax - NODE_DY,
-                       iconbutw,
-                       UI_UNIT_Y,
-                       NULL,
-                       0,
-                       0,
-                       0,
-                       0,
-                       "");
+    uiBut *but = uiDefIconBut(node->block,
+                              UI_BTYPE_BUT_TOGGLE,
+                              B_REDR,
+                              ICON_MATERIAL,
+                              iconofs,
+                              rct->ymax - NODE_DY,
+                              iconbutw,
+                              UI_UNIT_Y,
+                              NULL,
+                              0,
+                              0,
+                              0,
+                              0,
+                              "");
     UI_but_func_set(but, node_toggle_button_cb, node, (void *)"NODE_OT_preview_toggle");
     /* XXX this does not work when node is activated and the operator called right afterwards,
      * since active ID is not updated yet (needs to process the notifier).
@@ -1190,23 +1187,22 @@ static void node_draw_basis(const bContext *C,
   }
   /* group edit */
   if (node->type == NODE_GROUP) {
-    uiBut *but;
     iconofs -= iconbutw;
     UI_block_emboss_set(node->block, UI_EMBOSS_NONE);
-    but = uiDefIconBut(node->block,
-                       UI_BTYPE_BUT_TOGGLE,
-                       B_REDR,
-                       ICON_NODETREE,
-                       iconofs,
-                       rct->ymax - NODE_DY,
-                       iconbutw,
-                       UI_UNIT_Y,
-                       NULL,
-                       0,
-                       0,
-                       0,
-                       0,
-                       "");
+    uiBut *but = uiDefIconBut(node->block,
+                              UI_BTYPE_BUT_TOGGLE,
+                              B_REDR,
+                              ICON_NODETREE,
+                              iconofs,
+                              rct->ymax - NODE_DY,
+                              iconbutw,
+                              UI_UNIT_Y,
+                              NULL,
+                              0,
+                              0,
+                              0,
+                              0,
+                              "");
     UI_but_func_set(but, node_toggle_button_cb, node, (void *)"NODE_OT_group_edit");
     UI_block_emboss_set(node->block, UI_EMBOSS);
   }
@@ -1240,24 +1236,23 @@ static void node_draw_basis(const bContext *C,
 
   /* open/close entirely? */
   {
-    uiBut *but;
     int but_size = U.widget_unit * 0.8f;
     /* XXX button uses a custom triangle draw below, so make it invisible without icon */
     UI_block_emboss_set(node->block, UI_EMBOSS_NONE);
-    but = uiDefBut(node->block,
-                   UI_BTYPE_BUT_TOGGLE,
-                   B_REDR,
-                   "",
-                   rct->xmin + 0.35f * U.widget_unit,
-                   rct->ymax - NODE_DY / 2.2f - but_size / 2,
-                   but_size,
-                   but_size,
-                   NULL,
-                   0,
-                   0,
-                   0,
-                   0,
-                   "");
+    uiBut *but = uiDefBut(node->block,
+                          UI_BTYPE_BUT_TOGGLE,
+                          B_REDR,
+                          "",
+                          rct->xmin + 0.35f * U.widget_unit,
+                          rct->ymax - NODE_DY / 2.2f - but_size / 2,
+                          but_size,
+                          but_size,
+                          NULL,
+                          0,
+                          0,
+                          0,
+                          0,
+                          "");
     UI_but_func_set(but, node_toggle_button_cb, node, (void *)"NODE_OT_hide_toggle");
     UI_block_emboss_set(node->block, UI_EMBOSS);
 
@@ -1412,24 +1407,23 @@ static void node_draw_hidden(const bContext *C,
 
   /* open entirely icon */
   {
-    uiBut *but;
     int but_size = U.widget_unit * 0.8f;
     /* XXX button uses a custom triangle draw below, so make it invisible without icon */
     UI_block_emboss_set(node->block, UI_EMBOSS_NONE);
-    but = uiDefBut(node->block,
-                   UI_BTYPE_BUT_TOGGLE,
-                   B_REDR,
-                   "",
-                   rct->xmin + 0.35f * U.widget_unit,
-                   centy - but_size / 2,
-                   but_size,
-                   but_size,
-                   NULL,
-                   0,
-                   0,
-                   0,
-                   0,
-                   "");
+    uiBut *but = uiDefBut(node->block,
+                          UI_BTYPE_BUT_TOGGLE,
+                          B_REDR,
+                          "",
+                          rct->xmin + 0.35f * U.widget_unit,
+                          centy - but_size / 2,
+                          but_size,
+                          but_size,
+                          NULL,
+                          0,
+                          0,
+                          0,
+                          0,
+                          "");
     UI_but_func_set(but, node_toggle_button_cb, node, (void *)"NODE_OT_hide_toggle");
     UI_block_emboss_set(node->block, UI_EMBOSS);
 
@@ -1609,11 +1603,8 @@ void node_draw_nodetree(const bContext *C,
 #endif
 
   /* draw background nodes, last nodes in front */
-  int a;
-  bNode *node;
-  for (a = 0, node = ntree->nodes.first; node; node = node->next, a++) {
-    bNodeInstanceKey key;
-
+  int a = 0;
+  LISTBASE_FOREACH_INDEX (bNode *, node, &ntree->nodes, a) {
 #ifdef USE_DRAW_TOT_UPDATE
     /* unrelated to background nodes, update the v2d->tot,
      * can be anywhere before we draw the scroll bars */
@@ -1624,7 +1615,7 @@ void node_draw_nodetree(const bContext *C,
       continue;
     }
 
-    key = BKE_node_instance_key(parent_key, ntree, node);
+    bNodeInstanceKey key = BKE_node_instance_key(parent_key, ntree, node);
     node->nr = a; /* index of node in list, used for exec event code */
     node_draw(C, region, snode, ntree, node, key);
   }
@@ -1641,13 +1632,13 @@ void node_draw_nodetree(const bContext *C,
   GPU_blend(GPU_BLEND_NONE);
 
   /* draw foreground nodes, last nodes in front */
-  for (a = 0, node = ntree->nodes.first; node; node = node->next, a++) {
-    bNodeInstanceKey key;
+  a = 0;
+  LISTBASE_FOREACH_INDEX (bNode *, node, &ntree->nodes, a) {
     if (node->flag & NODE_BACKGROUND) {
       continue;
     }
 
-    key = BKE_node_instance_key(parent_key, ntree, node);
+    bNodeInstanceKey key = BKE_node_instance_key(parent_key, ntree, node);
     node->nr = a; /* index of node in list, used for exec event code */
     node_draw(C, region, snode, ntree, node, key);
   }
@@ -1695,7 +1686,6 @@ static void draw_group_overlay(const bContext *C, ARegion *region)
 {
   View2D *v2d = &region->v2d;
   rctf rect = v2d->cur;
-  uiBlock *block;
   float color[4];
 
   /* shade node groups to separate them visually */
@@ -1707,7 +1697,7 @@ static void draw_group_overlay(const bContext *C, ARegion *region)
   GPU_blend(GPU_BLEND_NONE);
 
   /* set the block bounds to clip mouse events from underlying nodes */
-  block = UI_block_begin(C, region, "node tree bounds block", UI_EMBOSS);
+  uiBlock *block = UI_block_begin(C, region, "node tree bounds block", UI_EMBOSS);
   UI_block_bounds_set_explicit(block, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
   UI_block_flag_enable(block, UI_BLOCK_CLIP_EVENTS);
   UI_block_end(C, block);
@@ -1752,14 +1742,8 @@ void node_draw_space(const bContext *C, ARegion *region)
   /* draw parent node trees */
   if (snode->treepath.last) {
     static const int max_depth = 2;
-    bNodeTreePath *path;
-    int depth, curdepth;
-    float center[2];
-    bNodeTree *ntree;
-    bNodeLinkDrag *nldrag;
-    LinkData *linkdata;
 
-    path = snode->treepath.last;
+    bNodeTreePath *path = snode->treepath.last;
 
     /* update tree path name (drawn in the bottom left) */
     ID *name_id = (path->nodetree && path->nodetree != snode->nodetree) ? &path->nodetree->id :
@@ -1770,6 +1754,7 @@ void node_draw_space(const bContext *C, ARegion *region)
     }
 
     /* current View2D center, will be set temporarily for parent node trees */
+    float center[2];
     UI_view2d_center_get(v2d, &center[0], &center[1]);
 
     /* store new view center in path and current edittree */
@@ -1778,15 +1763,15 @@ void node_draw_space(const bContext *C, ARegion *region)
       copy_v2_v2(snode->edittree->view_center, center);
     }
 
-    depth = 0;
+    int depth = 0;
     while (path->prev && depth < max_depth) {
       path = path->prev;
       depth++;
     }
 
     /* parent node trees in the background */
-    for (curdepth = depth; curdepth > 0; path = path->next, curdepth--) {
-      ntree = path->nodetree;
+    for (int curdepth = depth; curdepth > 0; path = path->next, curdepth--) {
+      bNodeTree *ntree = path->nodetree;
       if (ntree) {
         snode_setup_v2d(snode, region, path->view_center);
 
@@ -1797,7 +1782,7 @@ void node_draw_space(const bContext *C, ARegion *region)
     }
 
     /* top-level edit tree */
-    ntree = path->nodetree;
+    bNodeTree *ntree = path->nodetree;
     if (ntree) {
       snode_setup_v2d(snode, region, center);
 
@@ -1832,8 +1817,8 @@ void node_draw_space(const bContext *C, ARegion *region)
     /* temporary links */
     GPU_blend(GPU_BLEND_ALPHA);
     GPU_line_smooth(true);
-    for (nldrag = snode->linkdrag.first; nldrag; nldrag = nldrag->next) {
-      for (linkdata = nldrag->links.first; linkdata; linkdata = linkdata->next) {
+    LISTBASE_FOREACH (bNodeLinkDrag *, nldrag, &snode->linkdrag) {
+      LISTBASE_FOREACH (LinkData *, linkdata, &nldrag->links) {
         node_draw_link(v2d, snode, (bNodeLink *)linkdata->data);
       }
     }