Add background and border attributes to Text canvas object

doc/WhatsNew.rst

@@ -22,6 +22,9 @@ Ver 5.2.0 (unreleased)
   - Toolbar and Info (Synopsis) bars change GUIs according to which
     viewer is active in the channel
 
+- Text canvas type gets new attributes: bgcolor, bgalpha, bordercolor,
+  borderpadding, borderalpha, borderlinewidth
+
 Ver 5.1.0 (2024-05-22)
 ======================
 - Fixed an issue where --modules option did not start a global plugin

ginga/canvas/types/basic.py

@@ -76,6 +76,24 @@ def get_params_metadata(cls):
             Param(name='fillalpha', type=float, default=1.0,
                   min=0.0, max=1.0, widget='spinfloat', incr=0.05,
                   description="Opacity of fill"),
+            Param(name='bgcolor',
+                  valid=colors_plus_none, type=_color, default='white',
+                  description="Color of text background"),
+            Param(name='bgalpha', type=float, default=0.0,
+                  min=0.0, max=1.0, widget='spinfloat', incr=0.05,
+                  description="Opacity of text background"),
+            Param(name='bordercolor',
+                  valid=colors_plus_none, type=_color, default='black',
+                  description="Color of text border"),
+            Param(name='borderlinewidth', type=int, default=0,
+                  min=0, max=20, widget='spinbutton', incr=1,
+                  description="Width of border"),
+            Param(name='borderpadding', type=int, default=4,
+                  min=0, max=20, widget='spinbutton', incr=1,
+                  description="Padding from text to border"),
+            Param(name='borderalpha', type=float, default=0.0,
+                  min=0.0, max=1.0, widget='spinfloat', incr=0.05,
+                  description="Opacity of text border"),
             Param(name='rot_deg', type=float, default=0.0,
                   min=-359.999, max=359.999, widget='spinfloat', incr=1.0,
                   description="Rotation of text"),
@@ -92,7 +110,9 @@ def __init__(self, pt, text='EDIT ME',
                  font='Sans Serif', fontsize=None, fontscale=False,
                  fill=True, fontsize_min=6.0, fontsize_max=None,
                  color='yellow', alpha=1.0, fillcolor=None, fillalpha=1.0,
-                 linewidth=0, rot_deg=0.0, showcap=False, **kwdargs):
+                 linewidth=0, rot_deg=0.0, bgcolor='white', bgalpha=0.0,
+                 bordercolor='black', borderpadding=4,
+                 borderlinewidth=0, borderalpha=0.0, showcap=False, **kwdargs):
         self.kind = 'text'
         if fillcolor is None:
             fillcolor = color
@@ -104,6 +124,11 @@ def __init__(self, pt, text='EDIT ME',
                                     fontsize_min=fontsize_min,
                                     fontsize_max=fontsize_max,
                                     text=text, rot_deg=rot_deg,
+                                    bgcolor=bgcolor, bgalpha=bgalpha,
+                                    bordercolor=bordercolor,
+                                    borderpadding=borderpadding,
+                                    borderlinewidth=borderlinewidth,
+                                    borderalpha=borderalpha,
                                     showcap=showcap, **kwdargs)
         OnePointMixin.__init__(self)
 
@@ -170,10 +195,28 @@ def get_llur(self):
 
     def draw(self, viewer):
         cr = viewer.renderer.setup_cr(self)
-        cr.initialize_from_shape(self, line=True, fill=True, font=True)
+        cr.initialize_from_shape(self, line=False, fill=False, font=True)
 
         x, y = self.get_data_points()[0]
         cx, cy = viewer.get_canvas_xy(x, y)
+
+        # draw background/border
+        if self.borderalpha + self.bgalpha > 0.0:
+            cwd, cht = cr.text_extents(self.text)
+            pad = self.borderpadding
+            bbox = np.array([(cx - pad, cy + pad), (cx + cwd + pad, cy + pad),
+                             (cx + cwd + pad, cy - cht - pad),
+                             (cx - pad, cy - cht - pad)])
+            x_arr, y_arr = bbox.T
+            xa, ya = trcalc.rotate_pt(x_arr, y_arr, -self.rot_deg,
+                                      xoff=cx, yoff=cy)
+            cpoints = np.array((xa, ya)).T
+            cr.set_line(self.bordercolor, alpha=self.borderalpha,
+                        linewidth=self.borderlinewidth)
+            cr.set_fill(self.bgcolor, alpha=self.bgalpha)
+            cr.draw_polygon(cpoints, line=cr.line, fill=cr.fill)
+
+        cr.initialize_from_shape(self, line=True, fill=True, font=False)
         cr.draw_text(cx, cy, self.text, rot_deg=self.rot_deg,
                      font=cr.font, fill=cr.fill, line=cr.line)
 
@@ -188,15 +231,21 @@ def __init__(self, x, y, text='EDIT ME',
                  font='Sans Serif', fontsize=None, fontscale=False,
                  fontsize_min=6.0, fontsize_max=None, fill=True,
                  color='yellow', alpha=1.0, fillcolor=None, fillalpha=1.0,
-                 linewidth=0, rot_deg=0.0, showcap=False, **kwdargs):
+                 linewidth=0, rot_deg=0.0, bgcolor='white', bgalpha=0.0,
+                 bordercolor='black', borderpadding=4,
+                 borderlinewidth=0, borderalpha=0.0, showcap=False, **kwdargs):
         if fillcolor is None:
             fillcolor = color
         TextP.__init__(self, (x, y), text=text, color=color, alpha=alpha,
                        fill=fill, fillcolor=fillcolor, fillalpha=fillalpha,
                        font=font, fontsize=fontsize, fontscale=fontscale,
                        fontsize_min=fontsize_min, fontsize_max=fontsize_max,
-                       linewidth=linewidth, rot_deg=rot_deg, showcap=showcap,
-                       **kwdargs)
+                       linewidth=linewidth, rot_deg=rot_deg,
+                       bgcolor=bgcolor, bgalpha=bgalpha,
+                       bordercolor=bordercolor, borderpadding=borderpadding,
+                       borderlinewidth=borderlinewidth,
+                       borderalpha=borderalpha,
+                       showcap=showcap, **kwdargs)
 
 
 class Polygon(PolygonMixin, CanvasObjectBase):

ginga/qtw/CanvasRenderQt.py

@@ -74,11 +74,8 @@ def text_extents(self, text, font=None):
         if font is None:
             font = self.font
         fm = QFontMetrics(font.render.font)
-        if hasattr(fm, 'horizontalAdvance'):
-            width = fm.horizontalAdvance(text)
-        else:
-            width = fm.width(text)
-        height = fm.height()
+        rect = fm.boundingRect(text)
+        width, height = rect.width(), fm.ascent()  # rect.height()
         return width, height
 
     ##### DRAWING OPERATIONS #####
@@ -95,14 +92,7 @@ def draw_text(self, cx, cy, text, rot_deg=0.0, font=None, fill=None,
 
         if font is not None:
             self.ctx.setFont(font.render.font)
-        # draw bg
         qfont = self.ctx.font()
-        # fm = QFontMetrics(qfont)
-        # qrect = fm.boundingRect(text)
-        # self.ctx.fillRect(qrect, self.ctx.brush())
-        # # draw fg
-        # self.ctx.drawText(0, 0, text)
-        #----------
         self.ctx.setBrush(QtCore.Qt.NoBrush if fill is None
                           else fill.render.brush)
 
@@ -322,11 +312,8 @@ def get_dimensions(self, shape):
     def text_extents(self, text, font):
         qfont = get_font(font.fontname, font.fontsize)
         fm = QFontMetrics(qfont)
-        if hasattr(fm, 'horizontalAdvance'):
-            width = fm.horizontalAdvance(text)
-        else:
-            width = fm.width(text)
-        height = fm.height()
+        rect = fm.boundingRect(text)
+        width, height = rect.width(), fm.ascent()   # rect.height()
         return width, height