Outliner: Correct outliner width computation

Before it was not possible to see everything in the outliner
when there are e.g. long icon rows. This is because Blender
did not allow panning the view to the right, since it did not
know the actual width.

Most of the code to compute the width correctly was there already,
but there were a couple of issues that made it not work.

* The tree width was computed before the tree was drawn.
This does not work, since the width is only known, after
it is drawn.
* Every `TreeElement` stores its right-most position in `xend`.
However, in the current code, the `xend` of e.g. an object is
the position where the text ends. The `xend` of the icons
is stored in the sub-tree-elements. Therefore, to compute
the maximum width, you may not skip the closed tree elements.
* The current drawing code had an early exit when the icon row
would not be visible anymore. This also skipped the calculation
of `xend`. So it would work correctly, when the icon was visible
a little bit, but not when it was not visible at all.

This patch fixes these issues. So even in more complex files, the
width is computed correcly. At least I haven't found a case, where
it does not.

Unfortunately, some optimizations had to be turned off, to make
it correct.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D4887

1 files changed, 58 insertions, 91 deletions

diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index aed7af3911f..13ec532c30c 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -82,58 +82,32 @@
 /* ****************************************************** */
 /* Tree Size Functions */
 
-static void outliner_height(SpaceOutliner *soops, ListBase *lb, int *h)
+static void outliner_tree_dimensions_impl(SpaceOutliner *soops,
+                                          ListBase *lb,
+                                          int *width,
+                                          int *height)
 {
-  TreeElement *te = lb->first;
-  while (te) {
+  for (TreeElement *te = lb->first; te; te = te->next) {
+    *width = MAX2(*width, te->xend);
+    if (height != NULL) {
+      *height += UI_UNIT_Y;
+    }
+
     TreeStoreElem *tselem = TREESTORE(te);
     if (TSELEM_OPEN(tselem, soops)) {
-      outliner_height(soops, &te->subtree, h);
+      outliner_tree_dimensions_impl(soops, &te->subtree, width, height);
     }
-    (*h) += UI_UNIT_Y;
-    te = te->next;
-  }
-}
-
-#if 0  // XXX this is currently disabled until te->xend is set correctly
-static void outliner_width(SpaceOutliner *soops, ListBase *lb, int *w)
-{
-  TreeElement *te = lb->first;
-  while (te) {
-    //      TreeStoreElem *tselem = TREESTORE(te);
-
-    // XXX fixme... te->xend is not set yet
-    if (!TSELEM_OPEN(tselem, soops)) {
-      if (te->xend > *w)
-        *w = te->xend;
+    else {
+      outliner_tree_dimensions_impl(soops, &te->subtree, width, NULL);
     }
-    outliner_width(soops, &te->subtree, w);
-    te = te->next;
   }
 }
-#endif
 
-static void outliner_rna_width(SpaceOutliner *soops, ListBase *lb, int *w, int startx)
+static void outliner_tree_dimensions(SpaceOutliner *soops, int *r_width, int *r_height)
 {
-  TreeElement *te = lb->first;
-  while (te) {
-    TreeStoreElem *tselem = TREESTORE(te);
-    // XXX fixme... (currently, we're using a fixed length of 100)!
-#if 0
-    if (te->xend) {
-      if (te->xend > *w)
-        *w = te->xend;
-    }
-#endif
-    if (startx + 100 > *w) {
-      *w = startx + 100;
-    }
-
-    if (TSELEM_OPEN(tselem, soops)) {
-      outliner_rna_width(soops, &te->subtree, w, startx + UI_UNIT_X);
-    }
-    te = te->next;
-  }
+  *r_width = 0;
+  *r_height = 0;
+  outliner_tree_dimensions_impl(soops, &soops->tree, r_width, r_height);
 }
 
 /**
@@ -2644,11 +2618,6 @@ static void outliner_draw_iconrow(bContext *C,
   const Object *obact = OBACT(view_layer);
 
   for (TreeElement *te = lb->first; te; te = te->next) {
-    /* exit drawing early */
-    if ((*offsx) - UI_UNIT_X > xmax) {
-      break;
-    }
-
     TreeStoreElem *tselem = TREESTORE(te);
 
     /* object hierarchy always, further constrained on level */
@@ -3381,6 +3350,36 @@ static void outliner_back(ARegion *ar)
   immUnbindProgram();
 }
 
+static int outliner_data_api_buttons_start_x(int max_tree_width)
+{
+  return max_ii(OL_RNA_COLX, max_tree_width + OL_RNA_COL_SPACEX);
+}
+
+static int outliner_width(SpaceOutliner *soops, int max_tree_width, float restrict_column_width)
+{
+  if (soops->outlinevis == SO_DATA_API) {
+    return outliner_data_api_buttons_start_x(max_tree_width) + OL_RNA_COL_SIZEX + 10 * UI_DPI_FAC;
+  }
+  else {
+    return max_tree_width + restrict_column_width;
+  }
+}
+
+static void outliner_update_viewable_area(ARegion *ar,
+                                          SpaceOutliner *soops,
+                                          int tree_width,
+                                          int tree_height,
+                                          float restrict_column_width)
+{
+  int sizex = outliner_width(soops, tree_width, restrict_column_width);
+  int sizey = tree_height;
+
+  /* extend size to allow for horizontal scrollbar and extra offset */
+  sizey += V2D_SCROLL_HEIGHT + OL_Y_OFFSET;
+
+  UI_view2d_totRect_set(&ar->v2d, sizex, sizey);
+}
+
 /* ****************************************************** */
 /* Main Entrypoint - Draw contents of Outliner editor */
 
@@ -3393,71 +3392,36 @@ void draw_outliner(const bContext *C)
   View2D *v2d = &ar->v2d;
   SpaceOutliner *soops = CTX_wm_space_outliner(C);
   uiBlock *block;
-  int sizey = 0, sizex = 0, sizex_rna = 0;
   TreeElement *te_edit = NULL;
 
   outliner_build_tree(mainvar, scene, view_layer, soops, ar);  // always
 
-  /* get extents of data */
-  outliner_height(soops, &soops->tree, &sizey);
-
-  /* extend size to allow for horizontal scrollbar */
-  sizey += V2D_SCROLL_HEIGHT;
-
-  const float restrict_column_width = outliner_restrict_columns_width(soops);
-  if (soops->outlinevis == SO_DATA_API) {
-    /* RNA has two columns:
-     * - column 1 is (max_width + OL_RNA_COL_SPACEX) or
-     *   (OL_RNA_COL_X), whichever is wider...
-     * - column 2 is fixed at OL_RNA_COL_SIZEX
-     *
-     *  (*) XXX max width for now is a fixed factor of (UI_UNIT_X * (max_indention + 100))
-     */
-
-    /* get actual width of column 1 */
-    outliner_rna_width(soops, &soops->tree, &sizex_rna, 0);
-    sizex_rna = max_ii(OL_RNA_COLX, sizex_rna + OL_RNA_COL_SPACEX);
-
-    /* get width of data (for setting 'tot' rect, this is column 1 + column 2 + a bit extra) */
-    sizex = sizex_rna + OL_RNA_COL_SIZEX + 50;
-  }
-  else {
-    /* width must take into account restriction columns (if visible)
-     * so that entries will still be visible */
-    // outliner_width(soops, &soops->tree, &sizex);
-    // XXX should use outliner_width instead when te->xend will be set correctly...
-    outliner_rna_width(soops, &soops->tree, &sizex, 0);
-
-    /* Constant offset for restriction columns */
-    sizex += restrict_column_width;
-  }
-
-  /* adds vertical offset */
-  sizey += OL_Y_OFFSET;
-
-  /* update size of tot-rect (extents of data/viewable area) */
-  UI_view2d_totRect_set(v2d, sizex, sizey);
-
   /* force display to pixel coords */
   v2d->flag |= (V2D_PIXELOFS_X | V2D_PIXELOFS_Y);
   /* set matrix for 2d-view controls */
   UI_view2d_view_ortho(v2d);
 
   /* draw outliner stuff (background, hierarchy lines and names) */
+  const float restrict_column_width = outliner_restrict_columns_width(soops);
   outliner_back(ar);
   block = UI_block_begin(C, ar, __func__, UI_EMBOSS);
   outliner_draw_tree(
       (bContext *)C, block, scene, view_layer, ar, soops, restrict_column_width, &te_edit);
 
+  /* Compute outliner dimensions after it has been drawn. */
+  int tree_width, tree_height;
+  outliner_tree_dimensions(soops, &tree_width, &tree_height);
+
   /* Default to no emboss for outliner UI. */
   UI_block_emboss_set(block, UI_EMBOSS_NONE);
 
   if (soops->outlinevis == SO_DATA_API) {
+    int buttons_start_x = outliner_data_api_buttons_start_x(tree_width);
     /* draw rna buttons */
-    outliner_draw_rnacols(ar, sizex_rna);
+    outliner_draw_rnacols(ar, buttons_start_x);
 
     UI_block_emboss_set(block, UI_EMBOSS);
-    outliner_draw_rnabuts(block, ar, soops, sizex_rna, &soops->tree);
+    outliner_draw_rnabuts(block, ar, soops, buttons_start_x, &soops->tree);
     UI_block_emboss_set(block, UI_EMBOSS_NONE);
   }
   else if (soops->outlinevis == SO_ID_ORPHANS) {
@@ -3480,4 +3444,7 @@ void draw_outliner(const bContext *C)
 
   UI_block_end(C, block);
   UI_block_draw(C, block);
+
+  /* Update total viewable region. */
+  outliner_update_viewable_area(ar, soops, tree_width, tree_height, restrict_column_width);
 }