[Maposmatic-dev] [PATCH 5/5] multi-page: add page number on overview page

[Étienne Loks]

---
 ocitysmap2/coords.py                        |   21 ++++++++++++++
 ocitysmap2/layoutlib/abstract_renderer.py   |   41 +++++++++++++++++++++++++++
 ocitysmap2/layoutlib/multi_page_renderer.py |   21 ++++++++------
 ocitysmap2/maplib/overview_grid.py          |    4 +-
 4 files changed, 76 insertions(+), 11 deletions(-)

diff --git a/ocitysmap2/coords.py b/ocitysmap2/coords.py
index cad307f..3050c71 100644
--- a/ocitysmap2/coords.py
+++ b/ocitysmap2/coords.py
@@ -25,6 +25,15 @@
 import math
 
 import shapely.wkt
+try:
+    import mapnik2 as mapnik
+except ImportError:
+    import mapnik
+
+_MAPNIK_PROJECTION = "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 " \
+                     "+lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m   " \
+                     "address@hidden +no_defs +over"
+
 
 EARTH_RADIUS = 6370986 # meters
 
@@ -155,6 +164,18 @@ class BoundingBox:
 
         return (int(math.ceil(pix_y)), int(math.ceil(pix_x)))
 
+    def to_mercator(self):
+        envelope = mapnik.Box2d(self.get_top_left()[1],
+                                self.get_top_left()[0],
+                                self.get_bottom_right()[1],
+                                self.get_bottom_right()[0])
+        _proj = mapnik.Projection(_MAPNIK_PROJECTION)
+        bottom_left = _proj.forward(mapnik.Coord(envelope.minx, envelope.miny))
+        top_right = _proj.forward(mapnik.Coord(envelope.maxx, envelope.maxy))
+        top_left = mapnik.Coord(bottom_left.x, top_right.y)
+        bottom_right = mapnik.Coord(top_right.x, bottom_left.y)
+        return (bottom_right, bottom_left, top_left, top_right)
+
     def as_javascript(self, name=None, color=None):
         if name:
             name_str = ", \"%s\"" % name
diff --git a/ocitysmap2/layoutlib/abstract_renderer.py 
b/ocitysmap2/layoutlib/abstract_renderer.py
index 4f7083f..a3feb7e 100644
--- a/ocitysmap2/layoutlib/abstract_renderer.py
+++ b/ocitysmap2/layoutlib/abstract_renderer.py
@@ -26,6 +26,10 @@ import math
 import os
 import sys
 import cairo
+try:
+    import mapnik2 as mapnik
+except ImportError:
+    import mapnik
 import pango
 import re
 
@@ -39,6 +43,8 @@ import logging
 
 LOG = logging.getLogger('ocitysmap')
 
+OVERVIEW_PAGE_STR = "Page %(page_number)d"
+
 class Renderer:
     """
     The job of an OCitySMap layout renderer is to lay out the resulting map and
@@ -213,6 +219,41 @@ class Renderer:
 
         ctx.restore()
 
+    @staticmethod
+    def _draw_overview_labels(ctx, map_canvas, overview_grid,
+                     area_width_dots, area_height_dots):
+        """
+        Draw the page numbers for the overview grid.
+
+        Args:
+           ctx (cairo.Context): The cairo context to use to draw.
+           overview_grid (OverViewGrid): the overview grid object
+           area_width_dots/area_height_dots (numbers): size of the
+              drawing area (cairo units).
+        """
+        ctx.save()
+
+        ctx.set_font_size(18)
+
+        bbox = map_canvas.get_actual_bounding_box()
+        bottom_right, bottom_left, top_left, top_right = bbox.to_mercator()
+        bottom, left = bottom_right.y, top_left.x
+        coord_delta_y = top_left.y - bottom_right.y
+        coord_delta_x = bottom_right.x - top_left.x
+        for idx, page_bb in enumerate(overview_grid._pages_bbox):
+            p_bottom_right, p_bottom_left, p_top_left, p_top_right = \
+                                                        page_bb.to_mercator()
+            center_x = p_top_left.x+(p_top_right.x-p_top_left.x)/2
+            center_y = p_bottom_left.y+(p_top_right.y-p_bottom_right.y)/2
+            y_percent = 100 - 100.0*(center_y - bottom)/coord_delta_y
+            y = int(area_height_dots*y_percent/100)
+
+            x_percent = 100.0*(center_x - left)/coord_delta_x
+            x = int(area_width_dots*x_percent/100)
+            Renderer._draw_centered_text(ctx,
+                                OVERVIEW_PAGE_STR % {'page_number':idx+2}, x, 
y)
+        ctx.restore()
+
     def _create_map_canvas(self, width, height, dpi,
                            draw_contour_shade = True):
         """
diff --git a/ocitysmap2/layoutlib/multi_page_renderer.py 
b/ocitysmap2/layoutlib/multi_page_renderer.py
index b69fd3a..5f57816 100644
--- a/ocitysmap2/layoutlib/multi_page_renderer.py
+++ b/ocitysmap2/layoutlib/multi_page_renderer.py
@@ -55,10 +55,6 @@ from indexlib.commons import IndexCategory
 LOG = logging.getLogger('ocitysmap')
 PAGE_STR = " - Page %(page_number)d"
 
-_MAPNIK_PROJECTION = "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 " \
-                     "+lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m   " \
-                     "address@hidden +no_defs +over"
-
 class MultiPageRenderer(Renderer):
     """
     This Renderer creates a multi-pages map, with all the classic overlayed
@@ -90,7 +86,7 @@ class MultiPageRenderer(Renderer):
         # print self.rc.bounding_box.as_javascript("original", "#00ff00")
 
         # Convert the original Bounding box into Mercator meters
-        self._proj = mapnik.Projection(_MAPNIK_PROJECTION)
+        self._proj = mapnik.Projection(coords._MAPNIK_PROJECTION)
         orig_envelope = self._project_envelope(self.rc.bounding_box)
 
         # Extend the bounding box to take into account the lost outter
@@ -222,7 +218,7 @@ class MultiPageRenderer(Renderer):
                                   self.rc.stylesheet.grid_line_width)
 
         map_canvas.render()
-        self.pages.append((map_canvas, None))
+        self.pages.append((map_canvas, None, map_grid))
 
         # Create the map canvas for each page
         indexes = []
@@ -255,7 +251,7 @@ class MultiPageRenderer(Renderer):
                                       self.rc.stylesheet.grid_line_width)
 
             map_canvas.render()
-            self.pages.append((map_canvas, map_grid))
+            self.pages.append((map_canvas, map_grid, None))
 
             # Create the index for the current page
             index = StreetIndex(self.db,
@@ -352,7 +348,7 @@ class MultiPageRenderer(Renderer):
 
     def render(self, cairo_surface, dpi, osm_date):
         ctx = cairo.Context(cairo_surface)
-        for i, (canvas, grid) in enumerate(self.pages):
+        for i, (canvas, grid, overview_grid) in enumerate(self.pages):
             ctx.save()
 
             # Prepare to draw the map at the right location
@@ -373,8 +369,15 @@ class MultiPageRenderer(Renderer):
             ctx.translate(commons.convert_pt_to_dots(self.grayed_margin_pt),
                           commons.convert_pt_to_dots(self.grayed_margin_pt))
 
-            # Place the vertical and horizontal square labels
+            if overview_grid:
+                # draw pages numbers
+                self._draw_overview_labels(ctx, canvas, overview_grid,
+                  commons.convert_pt_to_dots(self._usable_area_width_pt) \
+                        - 2 * 
commons.convert_pt_to_dots(self.grayed_margin_pt),
+                  commons.convert_pt_to_dots(self._usable_area_height_pt) \
+                        - 2 * 
commons.convert_pt_to_dots(self.grayed_margin_pt))
             if grid:
+                # Place the vertical and horizontal square labels
                 self._draw_labels(ctx, grid,
                   commons.convert_pt_to_dots(self._usable_area_width_pt) \
                         - 2 * 
commons.convert_pt_to_dots(self.grayed_margin_pt),
diff --git a/ocitysmap2/maplib/overview_grid.py 
b/ocitysmap2/maplib/overview_grid.py
index fdde50a..c45762c 100644
--- a/ocitysmap2/maplib/overview_grid.py
+++ b/ocitysmap2/maplib/overview_grid.py
@@ -34,8 +34,6 @@ class OverviewGrid:
         l.info('Laying out of overview grid on %.1fx%.1fm area...' %
                (self._width_m, self._height_m))
 
-        self._pages_wkt = [bb.as_wkt() for bb in self._pages_bbox]
-
     def generate_shape_file(self, filename):
         """Generates the grid shapefile with all the horizontal and
         vertical lines added.
@@ -53,6 +51,8 @@ class OverviewGrid:
         map(g.add_box, self._pages_bbox)
         return g
 
+
+
 if __name__ == "__main__":
     logging.basicConfig(level=logging.DEBUG)
     pass
-- 
1.7.9.1