Add plot_title/caption_position themeables

closes #838

doc/_quartodoc.yml

@@ -458,13 +458,15 @@ quartodoc:
         - panel_spacing_y
         - plot_background
         - plot_caption
+        - plot_caption_position
         - plot_margin
         - plot_margin_bottom
         - plot_margin_left
         - plot_margin_right
         - plot_margin_top
         - plot_subtitle
         - plot_title
+        - plot_title_position
         - rect
         - strip_align
         - strip_align_x

doc/changelog.qmd

@@ -1,6 +1,27 @@
 ---
 title: Changelog
 ---
+---
+## v0.15.0
+(not-yet-released)
+
+### New Features
+
+- Using
+  [](:class:`~plotnine.themes.themeables.plot_title_position`) and
+  [](:class:`~plotnine.themes.themeables.plot_caption_position`) e.g.
+
+  ```python
+  theme(
+     plot_title_position="plot",
+     plot_caption_position="plot",
+  )
+  ```
+
+  You can now position the `plot_title`, `plot_subtitle` and `plot_caption`
+  by alignment them with respect to the plot. ({{< issue 838 >}})
+
+
 ## v0.14.1
 (2024-11-05)
 

plotnine/_mpl/layout_manager/_layout_items.py

@@ -450,31 +450,39 @@ def _adjust_positions(self, spaces: LayoutSpaces):
         Set the x,y position of the artists around the panels
         """
         theme = self.plot.theme
+        plot_title_position = theme.getp("plot_title_position", "panel")
+        plot_caption_position = theme.getp("plot_caption_position", "panel")
 
         if self.plot_title:
             ha = theme.getp(("plot_title", "ha"))
             self.plot_title.set_y(spaces.t.edge("plot_title"))
-            horizontally_align_text_with_panels(self.plot_title, ha, spaces)
+            horizontally_align_text(
+                self.plot_title, ha, spaces, plot_title_position
+            )
 
         if self.plot_subtitle:
             ha = theme.getp(("plot_subtitle", "ha"))
             self.plot_subtitle.set_y(spaces.t.edge("plot_subtitle"))
-            horizontally_align_text_with_panels(self.plot_subtitle, ha, spaces)
+            horizontally_align_text(
+                self.plot_subtitle, ha, spaces, plot_title_position
+            )
 
         if self.plot_caption:
             ha = theme.getp(("plot_caption", "ha"), "right")
             self.plot_caption.set_y(spaces.b.edge("plot_caption"))
-            horizontally_align_text_with_panels(self.plot_caption, ha, spaces)
+            horizontally_align_text(
+                self.plot_caption, ha, spaces, plot_caption_position
+            )
 
         if self.axis_title_x:
             ha = theme.getp(("axis_title_x", "ha"), "center")
             self.axis_title_x.set_y(spaces.b.edge("axis_title_x"))
-            horizontally_align_text_with_panels(self.axis_title_x, ha, spaces)
+            horizontally_align_text(self.axis_title_x, ha, spaces)
 
         if self.axis_title_y:
             va = theme.getp(("axis_title_y", "va"), "center")
             self.axis_title_y.set_x(spaces.l.edge("axis_title_y"))
-            vertically_align_text_with_panels(self.axis_title_y, va, spaces)
+            vertically_align_text(self.axis_title_y, va, spaces)
 
         if self.legends:
             set_legends_position(self.legends, spaces)
@@ -487,13 +495,17 @@ def _text_is_visible(text: Text) -> bool:
     return text.get_visible() and text._text  # type: ignore
 
 
-def horizontally_align_text_with_panels(
-    text: Text, ha: str | float, spaces: LayoutSpaces
+def horizontally_align_text(
+    text: Text,
+    ha: str | float,
+    spaces: LayoutSpaces,
+    how: Literal["panel", "plot"] = "panel",
 ):
     """
     Horizontal justification
 
-    Reinterpret horizontal alignment to be justification about the panels.
+    Reinterpret horizontal alignment to be justification about the panels or
+    the plot (depending on the how parameter)
     """
     if isinstance(ha, str):
         lookup = {
@@ -505,20 +517,30 @@ def horizontally_align_text_with_panels(
     else:
         f = ha
 
-    params = spaces.gsparams
+    if how == "panel":
+        left = spaces.l.left
+        right = spaces.r.right
+    else:
+        left = spaces.l.plot_left
+        right = spaces.r.plot_right
+
     width = spaces.items.calc.width(text)
-    x = params.left * (1 - f) + (params.right - width) * f
+    x = left * (1 - f) + (right - width) * f
     text.set_x(x)
     text.set_horizontalalignment("left")
 
 
-def vertically_align_text_with_panels(
-    text: Text, va: str | float, spaces: LayoutSpaces
+def vertically_align_text(
+    text: Text,
+    va: str | float,
+    spaces: LayoutSpaces,
+    how: Literal["panel", "plot"] = "panel",
 ):
     """
     Vertical justification
 
-    Reinterpret vertical alignment to be justification about the panels.
+    Reinterpret vertical alignment to be justification about the panels or
+    the plot (depending on the how parameter).
     """
     if isinstance(va, str):
         lookup = {
@@ -532,9 +554,15 @@ def vertically_align_text_with_panels(
     else:
         f = va
 
-    params = spaces.gsparams
+    if how == "panel":
+        top = spaces.t.top
+        bottom = spaces.b.bottom
+    else:
+        top = spaces.t.plot_top
+        bottom = spaces.b.plot_bottom
+
     height = spaces.items.calc.height(text)
-    y = params.bottom * (1 - f) + (params.top - height) * f
+    y = bottom * (1 - f) + (top - height) * f
     text.set_y(y)
     text.set_verticalalignment("bottom")
 

plotnine/_mpl/layout_manager/_spaces.py

@@ -173,6 +173,20 @@ def edge(self, item: str) -> float:
         """
         return self.sum_upto(item)
 
+    @property
+    def left(self):
+        """
+        Left of the panels in figure space
+        """
+        return self.total
+
+    @property
+    def plot_left(self):
+        """
+        Distance in figure space from left edge upto where artists start
+        """
+        return self.edge("legend")
+
 
 @dataclass
 class right_spaces(_side_spaces):
@@ -219,6 +233,20 @@ def edge(self, item: str) -> float:
         """
         return 1 - self.sum_upto(item)
 
+    @property
+    def right(self):
+        """
+        Right of the panels in figure space
+        """
+        return 1 - self.total
+
+    @property
+    def plot_right(self):
+        """
+        Distance in figure space from right edge upto where artists start
+        """
+        return self.edge("legend")
+
 
 @dataclass
 class top_spaces(_side_spaces):
@@ -284,6 +312,20 @@ def edge(self, item: str) -> float:
         """
         return 1 - self.sum_upto(item)
 
+    @property
+    def top(self):
+        """
+        Top of the panels in figure space
+        """
+        return 1 - self.total
+
+    @property
+    def plot_top(self):
+        """
+        Distance in figure space from top edge upto where artists start
+        """
+        return self.edge("legend")
+
 
 @dataclass
 class bottom_spaces(_side_spaces):
@@ -353,6 +395,20 @@ def edge(self, item: str) -> float:
         """
         return self.sum_upto(item)
 
+    @property
+    def bottom(self):
+        """
+        Bottom of the panels in figure space
+        """
+        return self.total
+
+    @property
+    def plot_bottom(self):
+        """
+        Distance in figure space from bottom edge upto where artists start
+        """
+        return self.edge("legend")
+
 
 @dataclass
 class LayoutSpaces:
@@ -434,34 +490,6 @@ def __post_init__(self):
                 # Increase aspect ratio, wider panels
                 self._reduce_height(ratio)
 
-    @property
-    def left(self):
-        """
-        Left of the panels in figure space
-        """
-        return self.l.total
-
-    @property
-    def right(self):
-        """
-        Right of the panels in figure space
-        """
-        return 1 - self.r.total
-
-    @property
-    def top(self):
-        """
-        Top of the panels in figure space
-        """
-        return 1 - self.t.total
-
-    @property
-    def bottom(self):
-        """
-        Bottom of the panels in figure space
-        """
-        return self.b.total
-
     def increase_horizontal_plot_margin(self, dw: float):
         """
         Increase the plot_margin to the right & left of the panels
@@ -494,7 +522,12 @@ def _calculate_panel_spacing(self) -> GridSpecParams:
             raise TypeError(f"Unknown type of facet: {type(self.plot.facet)}")
 
         return GridSpecParams(
-            self.left, self.right, self.top, self.bottom, wspace, hspace
+            self.l.left,
+            self.r.right,
+            self.t.top,
+            self.b.bottom,
+            wspace,
+            hspace,
         )
 
     def _calculate_panel_spacing_facet_grid(self) -> tuple[float, float]:
@@ -513,8 +546,8 @@ def _calculate_panel_spacing_facet_grid(self) -> tuple[float, float]:
         self.sh = theme.getp("panel_spacing_y") * self.W / self.H
 
         # width and height of axes as fraction of figure width & height
-        self.w = ((self.right - self.left) - self.sw * (ncol - 1)) / ncol
-        self.h = ((self.top - self.bottom) - self.sh * (nrow - 1)) / nrow
+        self.w = ((self.r.right - self.l.left) - self.sw * (ncol - 1)) / ncol
+        self.h = ((self.t.top - self.b.bottom) - self.sh * (nrow - 1)) / nrow
 
         # Spacing as fraction of axes width & height
         wspace = self.sw / self.w
@@ -559,8 +592,8 @@ def _calculate_panel_spacing_facet_wrap(self) -> tuple[float, float]:
             ) + self.items.axis_ticks_y_max_width("all")
 
         # width and height of axes as fraction of figure width & height
-        self.w = ((self.right - self.left) - self.sw * (ncol - 1)) / ncol
-        self.h = ((self.top - self.bottom) - self.sh * (nrow - 1)) / nrow
+        self.w = ((self.r.right - self.l.left) - self.sw * (ncol - 1)) / ncol
+        self.h = ((self.t.top - self.b.bottom) - self.sh * (nrow - 1)) / nrow
 
         # Spacing as fraction of axes width & height
         wspace = self.sw / self.w
@@ -571,8 +604,8 @@ def _calculate_panel_spacing_facet_null(self) -> tuple[float, float]:
         """
         Calculate spacing parts for facet_null
         """
-        self.w = self.right - self.left
-        self.h = self.top - self.bottom
+        self.w = self.r.right - self.l.left
+        self.h = self.t.top - self.b.bottom
         self.sw = 0
         self.sh = 0
         return 0, 0

plotnine/themes/theme.py

@@ -122,6 +122,8 @@ def __init__(
         plot_title=None,
         plot_subtitle=None,
         plot_caption=None,
+        plot_title_position=None,
+        plot_caption_position=None,
         strip_text_x=None,
         strip_text_y=None,
         strip_text=None,

plotnine/themes/theme_gray.py

@@ -126,6 +126,8 @@ def __init__(self, base_size=11, base_family=None):
                 ma="left",
                 margin={"b": m, "units": "fig"},
             ),
+            plot_title_position="panel",
+            plot_caption_position="panel",
             strip_align=0,
             strip_background=element_rect(color="none", fill="#D9D9D9"),
             strip_background_x=element_rect(width=1),

plotnine/themes/theme_matplotlib.py

@@ -104,6 +104,8 @@ def __init__(self, rc=None, fname=None, use_defaults=True):
                 ma="left",
                 margin={"b": m, "units": "fig"},
             ),
+            plot_title_position="panel",
+            plot_caption_position="panel",
             strip_align=0,
             strip_background=element_rect(
                 fill="#D9D9D9", color="black", size=linewidth

plotnine/themes/theme_seaborn.py

@@ -116,6 +116,8 @@ def __init__(
                 ma="left",
                 margin={"b": m, "units": "fig"},
             ),
+            plot_title_position="panel",
+            plot_caption_position="panel",
             strip_align=0,
             strip_background=element_rect(color="none", fill="#D1CDDF"),
             strip_text=element_text(

plotnine/themes/theme_void.py

@@ -93,6 +93,8 @@ def __init__(self, base_size=11, base_family=None):
                 ma="left",
                 margin={"b": m, "units": "fig"},
             ),
+            plot_title_position="panel",
+            plot_caption_position="panel",
             strip_align=0,
             strip_text=element_text(
                 color="#1A1A1A",