[goffice] GogLabel: band-aid for rotated text

[Morten Welinder <mortenw src gnome org>]

commit a42d6b847748d3ac3386132dcabb2568ce5f8d28
Author: Morten Welinder <terra gnome org>
Date:   Fri Jan 23 12:41:19 2015 -0500

    GogLabel: band-aid for rotated text

 goffice/graph/gog-label.c |   61 ++++++++++++++++++++++++++++----------------
 1 files changed, 39 insertions(+), 22 deletions(-)
---
diff --git a/goffice/graph/gog-label.c b/goffice/graph/gog-label.c
index 78d33f7..85515d4 100644
--- a/goffice/graph/gog-label.c
+++ b/goffice/graph/gog-label.c
@@ -288,23 +288,28 @@ gog_label_populate_editor (GogObject *gobj,
        gtk_grid_attach (GTK_GRID (grid),
                gtk_label_new_with_mnemonic (_("_Text:")), 0, 0, 1, 1);
        gtk_grid_attach (GTK_GRID (grid), editor_widget, 1, 0, 1, 1);
+
        w = gtk_check_button_new_with_label (_("Rotate frame with text"));
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (w), GOG_TEXT (gobj)->rotate_frame);
        g_signal_connect (w, "toggled", G_CALLBACK (rotate_frame_cb), gobj);
        gtk_grid_attach (GTK_GRID (grid), w, 0, 1, 2, 1);
+
        w = gtk_check_button_new_with_label (_("Display the text on several lines if needed"));
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (w), GOG_TEXT (gobj)->allow_wrap);
        g_signal_connect (w, "toggled", G_CALLBACK (wrap_cb), gobj);
        gtk_grid_attach (GTK_GRID (grid), w, 0, 2, 2, 1);
+
        w = gtk_check_button_new_with_label (_("Rotate background with text"));
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (w), GOG_TEXT (gobj)->rotate_bg);
        g_signal_connect (w, "toggled", G_CALLBACK (rotate_bg_cb), gobj);
        gtk_grid_attach (GTK_GRID (grid), w, 0, 3, 2, 1);
+
        w = gtk_check_button_new_with_label (_("Interpret text as markup"));
        gtk_widget_set_tooltip_text (w, _("Interpret the text as an HTML like markup as described at 
http://developer.gnome.org/pango/stable/PangoMarkupFormat.html";));
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (w), GOG_TEXT (gobj)->allow_markup);
        g_signal_connect (w, "toggled", G_CALLBACK (allow_markup_cb), gobj);
        gtk_grid_attach (GTK_GRID (grid), w, 0, 4, 2, 1);
+
        gtk_widget_show_all (grid);
 
        go_editor_add_page (editor, grid, _("Details"));
@@ -657,15 +662,13 @@ gog_text_view_natural_size (GogView *view, GogViewRequisition *req)
        req->w = req->h = 0.;
        if (str != NULL) {
                GOString *gostr = pl
-                       ? go_string_new_rich (str, -1,
-                                             gog_text_get_markup (text),
-                                             NULL)
+                       ? go_string_new_rich (str, -1, pl, NULL)
                        : NULL;
                GOStyle *style = go_style_dup (text->base.base.style);
                double rot = fabs (style->text_layout.angle / 180 * M_PI);
                if (rot > M_PI / 2.)
                        rot = M_PI - rot;
-           if (text->rotate_frame)
+               if (text->rotate_frame)
                        style->text_layout.angle = 0.;
                gog_renderer_push_style (view->renderer, style);
                /* for natural size, we never force wrapping so use -1 as max width */
@@ -701,15 +704,13 @@ gog_text_view_size_request (GogView *v,
        req->w = req->h = 0.;
        if (str != NULL) {
                GOString *gostr = pl
-                       ? go_string_new_rich (str, -1,
-                                             gog_text_get_markup (text),
-                                             NULL)
+                       ? go_string_new_rich (str, -1, pl, NULL)
                        : NULL;
                GOStyle *style = go_style_dup (text->base.base.style);
                double rot = fabs (style->text_layout.angle / 180 * M_PI);
                if (rot > M_PI / 2.)
                        rot = M_PI - rot;
-           if (text->rotate_frame)
+               if (text->rotate_frame)
                        style->text_layout.angle = 0.;
                gog_renderer_push_style (v->renderer, style);
                if (gostr) {
@@ -739,14 +740,31 @@ gog_text_view_render (GogView *view, GogViewAllocation const *bbox)
        GOStyle *style = text->base.base.style;
        char *str = gog_text_get_str (text);
        PangoAttrList *pl = gog_text_get_markup (text);
-       double w = text->allow_wrap? view->residual.w: -1.;
+       double w = -1;
+       double rotpi = style->text_layout.angle / 180;
+
+       if (text->allow_wrap) {
+               /*
+                * This is a band-aid necessitated by charts imported from
+                * xlsx files have wrapping on by default.
+                *
+                * It is mostly correct for horizontal and vertical text
+                * It is mostly correct for rotated single-line text
+                * It is poor for rotated multi-line text
+                *
+                * We may need some fancier line breaking to fix a rotated text
+                * into an axis-parallel rectangle.
+                */
+               double s = go_sinpi (rotpi), c = go_cospi (rotpi);
+               double w1 = c ? view->residual.w / fabs (c) : go_pinf;
+               double w2 = s ? view->residual.h / fabs (s) : go_pinf;
+               w = MIN (w1, w2);
+       }
 
        gog_renderer_push_style (view->renderer, style);
        if (str != NULL) {
                GOString *gostr = pl
-                       ? go_string_new_rich (str, -1,
-                                             gog_text_get_markup (text),
-                                             NULL)
+                       ? go_string_new_rich (str, -1, pl, NULL)
                        : NULL;
                double outline = gog_renderer_line_size (view->renderer,
                                                         goo->base.style->line.width);
@@ -756,7 +774,6 @@ gog_text_view_render (GogView *view, GogViewAllocation const *bbox)
                        GOStyle *rect_style = NULL;
                        double pad_x = gog_renderer_pt2r_x (view->renderer, goo->padding_pts);
                        double pad_y = gog_renderer_pt2r_y (view->renderer, goo->padding_pts);
-                       double rot = style->text_layout.angle / 180 * M_PI;
                        if (text->rotate_frame) {
                                rect_style = go_style_dup (text->base.base.style);
                                rect_style->text_layout.angle = 0.;
@@ -770,18 +787,18 @@ gog_text_view_render (GogView *view, GogViewAllocation const *bbox)
                        rect.w = aabr.w + 2. * outline + pad_x;
                        rect.h = aabr.h + 2. * outline + pad_y;
                        if (text->rotate_frame) {
-                               if (rot > 0.) {
-                                       if (rot > M_PI / 2.) {
-                                               rect.y += rect.w * sin (rot) - rect.h * cos (rot);
-                                               rect.x -= rect.w * cos (rot);
+                               if (rotpi > 0.) {
+                                       if (rotpi > 0.5) {
+                                               rect.y += rect.w * go_sinpi (rotpi) - rect.h * go_cospi 
(rotpi);
+                                               rect.x -= rect.w * go_cospi (rotpi);
                                        } else
-                                               rect.y += rect.w * sin (rot);
+                                               rect.y += rect.w * go_sinpi (rotpi);
                                } else {
-                                       if (rot < -M_PI / 2.) {
-                                               rect.y -= rect.h * cos (rot);
-                                               rect.x -= rect.w * cos (rot) + rect.h * sin (rot);
+                                       if (rotpi < -0.5) {
+                                               rect.y -= rect.h * go_cospi (rotpi);
+                                               rect.x -= rect.w * go_cospi (rotpi) + rect.h * go_sinpi 
(rotpi);
                                        } else
-                                               rect.x -= rect.h * sin (rot);
+                                               rect.x -= rect.h * go_sinpi (rotpi);
                                }
                                gog_renderer_pop_style (view->renderer);
                                g_object_unref (rect_style);