matplotlib · QuLogic · Sep 1, 2021 · Sep 1, 2021
diff --git a/.flake8 b/.flake8
@@ -123,8 +123,12 @@ per-file-ignores =
     examples/ticks_and_spines/date_concise_formatter.py: E402
     examples/user_interfaces/embedding_in_gtk3_panzoom_sgskip.py: E402
     examples/user_interfaces/embedding_in_gtk3_sgskip.py: E402
-    examples/user_interfaces/gtk_spreadsheet_sgskip.py: E402
+    examples/user_interfaces/embedding_in_gtk4_panzoom_sgskip.py: E402
+    examples/user_interfaces/embedding_in_gtk4_sgskip.py: E402
+    examples/user_interfaces/gtk3_spreadsheet_sgskip.py: E402
+    examples/user_interfaces/gtk4_spreadsheet_sgskip.py: E402
     examples/user_interfaces/mpl_with_glade3_sgskip.py: E402
-    examples/user_interfaces/pylab_with_gtk_sgskip.py: E402
+    examples/user_interfaces/pylab_with_gtk3_sgskip.py: E402
+    examples/user_interfaces/pylab_with_gtk4_sgskip.py: E402
     examples/user_interfaces/toolmanager_sgskip.py: E402
     examples/userdemo/pgf_preamble_sgskip.py: E402
diff --git a/doc/api/backend_gtk4_api.rst b/doc/api/backend_gtk4_api.rst
@@ -0,0 +1,16 @@
+**NOTE** These backends are not documented here, to avoid adding a dependency
+to building the docs.
+
+.. redirect-from:: /api/backend_gtk4agg_api
+.. redirect-from:: /api/backend_gtk4cairo_api
+
+
+:mod:`matplotlib.backends.backend_gtk4agg`
+==========================================
+
+.. module:: matplotlib.backends.backend_gtk4agg
+
+:mod:`matplotlib.backends.backend_gtk4cairo`
+============================================
+
+.. module:: matplotlib.backends.backend_gtk4cairo
diff --git a/doc/api/index_backend_api.rst b/doc/api/index_backend_api.rst
@@ -10,6 +10,7 @@
    backend_agg_api.rst
    backend_cairo_api.rst
    backend_gtk3_api.rst
+   backend_gtk4_api.rst
    backend_nbagg_api.rst
    backend_pdf_api.rst
    backend_pgf_api.rst

diff --git a/doc/devel/dependencies.rst b/doc/devel/dependencies.rst
@@ -42,9 +42,9 @@ and the capabilities they provide.
 
 * Tk_ (>= 8.4, != 8.6.0 or 8.6.1) [#]_: for the Tk-based backends.
 * PyQt6_ (>= 6.1), PySide6_, PyQt5_, or PySide2_: for the Qt-based backends.
-* PyGObject_: for the GTK3-based backends [#]_.
+* PyGObject_: for the GTK-based backends [#]_.
 * wxPython_ (>= 4) [#]_: for the wx-based backends.
-* pycairo_ (>= 1.11.0) or cairocffi_ (>= 0.8): for the GTK3 and/or cairo-based
+* pycairo_ (>= 1.11.0) or cairocffi_ (>= 0.8): for the GTK and/or cairo-based
   backends.
 * Tornado_: for the WebAgg backend.
 

diff --git a/examples/user_interfaces/embedding_in_gtk3_panzoom_sgskip.py b/examples/user_interfaces/embedding_in_gtk3_panzoom_sgskip.py
@@ -20,7 +20,7 @@
 win = Gtk.Window()
 win.connect("delete-event", Gtk.main_quit)
 win.set_default_size(400, 300)
-win.set_title("Embedding in GTK")
+win.set_title("Embedding in GTK3")
 
 fig = Figure(figsize=(5, 4), dpi=100)
 ax = fig.add_subplot(1, 1, 1)

diff --git a/examples/user_interfaces/embedding_in_gtk3_sgskip.py b/examples/user_interfaces/embedding_in_gtk3_sgskip.py
@@ -19,7 +19,7 @@
 win = Gtk.Window()
 win.connect("delete-event", Gtk.main_quit)
 win.set_default_size(400, 300)
-win.set_title("Embedding in GTK")
+win.set_title("Embedding in GTK3")
 
 fig = Figure(figsize=(5, 4), dpi=100)
 ax = fig.add_subplot()

diff --git a/examples/user_interfaces/embedding_in_gtk4_panzoom_sgskip.py b/examples/user_interfaces/embedding_in_gtk4_panzoom_sgskip.py
@@ -0,0 +1,51 @@
+"""
+===========================================
+Embedding in GTK4 with a navigation toolbar
+===========================================
+
+Demonstrate NavigationToolbar with GTK4 accessed via pygobject.
+"""
+
+import gi
+gi.require_version('Gtk', '4.0')
+from gi.repository import Gtk
+
+from matplotlib.backends.backend_gtk4 import (
+    NavigationToolbar2GTK4 as NavigationToolbar)
+from matplotlib.backends.backend_gtk4agg import (
+    FigureCanvasGTK4Agg as FigureCanvas)
+from matplotlib.figure import Figure
+import numpy as np
+
+
+def on_activate(app):
+    win = Gtk.ApplicationWindow(application=app)
+    win.set_default_size(400, 300)
+    win.set_title("Embedding in GTK4")
+
+    fig = Figure(figsize=(5, 4), dpi=100)
+    ax = fig.add_subplot(1, 1, 1)
+    t = np.arange(0.0, 3.0, 0.01)
+    s = np.sin(2*np.pi*t)
+    ax.plot(t, s)
+
+    vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
+    win.set_child(vbox)
+
+    # Add canvas to vbox
+    canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
+    canvas.set_hexpand(True)
+    canvas.set_vexpand(True)
+    vbox.append(canvas)
+
+    # Create toolbar
+    toolbar = NavigationToolbar(canvas, win)
+    vbox.append(toolbar)
+
+    win.show()
+
+
+app = Gtk.Application(
+    application_id='org.matplotlib.examples.EmbeddingInGTK4PanZoom')
+app.connect('activate', on_activate)
+app.run(None)
diff --git a/examples/user_interfaces/embedding_in_gtk4_sgskip.py b/examples/user_interfaces/embedding_in_gtk4_sgskip.py
@@ -0,0 +1,45 @@
+"""
+=================
+Embedding in GTK4
+=================
+
+Demonstrate adding a FigureCanvasGTK4Agg widget to a Gtk.ScrolledWindow using
+GTK4 accessed via pygobject.
+"""
+
+import gi
+gi.require_version('Gtk', '4.0')
+from gi.repository import Gtk
+
+from matplotlib.backends.backend_gtk4agg import (
+    FigureCanvasGTK4Agg as FigureCanvas)
+from matplotlib.figure import Figure
+import numpy as np
+
+
+def on_activate(app):
+    win = Gtk.ApplicationWindow(application=app)
+    win.set_default_size(400, 300)
+    win.set_title("Embedding in GTK4")
+
+    fig = Figure(figsize=(5, 4), dpi=100)
+    ax = fig.add_subplot()
+    t = np.arange(0.0, 3.0, 0.01)
+    s = np.sin(2*np.pi*t)
+    ax.plot(t, s)
+
+    # A scrolled margin goes outside the scrollbars and viewport.
+    sw = Gtk.ScrolledWindow(margin_top=10, margin_bottom=10,
+                            margin_start=10, margin_end=10)
+    win.set_child(sw)
+
+    canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
+    canvas.set_size_request(800, 600)
+    sw.set_child(canvas)
+
+    win.show()
+
+
+app = Gtk.Application(application_id='org.matplotlib.examples.EmbeddingInGTK4')
+app.connect('activate', on_activate)
+app.run(None)
diff --git a/...user_interfaces/gtk_spreadsheet_sgskip.py → ...ser_interfaces/gtk3_spreadsheet_sgskip.py b/...user_interfaces/gtk_spreadsheet_sgskip.py → ...ser_interfaces/gtk3_spreadsheet_sgskip.py
@@ -1,7 +1,7 @@
 """
-===============
-GTK Spreadsheet
-===============
+================
+GTK3 Spreadsheet
+================
 
 Example of embedding Matplotlib in an application and interacting with a
 treeview to store data.  Double click on an entry to update plot data.

diff --git a/examples/user_interfaces/gtk4_spreadsheet_sgskip.py b/examples/user_interfaces/gtk4_spreadsheet_sgskip.py
@@ -0,0 +1,91 @@
+"""
+================
+GTK4 Spreadsheet
+================
+
+Example of embedding Matplotlib in an application and interacting with a
+treeview to store data.  Double click on an entry to update plot data.
+"""
+
+import gi
+gi.require_version('Gtk', '4.0')
+gi.require_version('Gdk', '4.0')
+from gi.repository import Gtk
+
+from matplotlib.backends.backend_gtk4agg import FigureCanvas  # or gtk4cairo.
+
+from numpy.random import random
+from matplotlib.figure import Figure
+
+
+class DataManager(Gtk.ApplicationWindow):
+    num_rows, num_cols = 20, 10
+
+    data = random((num_rows, num_cols))
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.set_default_size(600, 600)
+
+        self.set_title('GtkListStore demo')
+
+        vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, homogeneous=False,
+                       spacing=8)
+        self.set_child(vbox)
+
+        label = Gtk.Label(label='Double click a row to plot the data')
+        vbox.append(label)
+
+        sw = Gtk.ScrolledWindow()
+        sw.set_has_frame(True)
+        sw.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC)
+        sw.set_hexpand(True)
+        sw.set_vexpand(True)
+        vbox.append(sw)
+
+        model = self.create_model()
+        self.treeview = Gtk.TreeView(model=model)
+        self.treeview.connect('row-activated', self.plot_row)
+        sw.set_child(self.treeview)
+
+        # Matplotlib stuff
+        fig = Figure(figsize=(6, 4), constrained_layout=True)
+
+        self.canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
+        self.canvas.set_hexpand(True)
+        self.canvas.set_vexpand(True)
+        vbox.append(self.canvas)
+        ax = fig.add_subplot()
+        self.line, = ax.plot(self.data[0, :], 'go')  # plot the first row
+
+        self.add_columns()
+
+    def plot_row(self, treeview, path, view_column):
+        ind, = path  # get the index into data
+        points = self.data[ind, :]
+        self.line.set_ydata(points)
+        self.canvas.draw()
+
+    def add_columns(self):
+        for i in range(self.num_cols):
+            column = Gtk.TreeViewColumn(str(i), Gtk.CellRendererText(), text=i)
+            self.treeview.append_column(column)
+
+    def create_model(self):
+        types = [float] * self.num_cols
+        store = Gtk.ListStore(*types)
+        for row in self.data:
+            # Gtk.ListStore.append is broken in PyGObject, so insert manually.
+            it = store.insert(-1)
+            store.set(it, {i: val for i, val in enumerate(row)})
+        return store
+
+
+def on_activate(app):
+    manager = DataManager(application=app)
+    manager.show()
+
+
+app = Gtk.Application(application_id='org.matplotlib.examples.GTK4Spreadsheet')
+app.connect('activate', on_activate)
+app.run()
diff --git a/.../user_interfaces/pylab_with_gtk_sgskip.py → ...user_interfaces/pylab_with_gtk3_sgskip.py b/.../user_interfaces/pylab_with_gtk_sgskip.py → ...user_interfaces/pylab_with_gtk3_sgskip.py
@@ -1,7 +1,7 @@
 """
-===============
-pyplot with GTK
-===============
+================
+pyplot with GTK3
+================
 
 An example of how to use pyplot to manage your figure windows, but modify the
 GUI by accessing the underlying GTK widgets.

diff --git a/examples/user_interfaces/pylab_with_gtk4_sgskip.py b/examples/user_interfaces/pylab_with_gtk4_sgskip.py
@@ -0,0 +1,51 @@
+"""
+================
+pyplot with GTK4
+================
+
+An example of how to use pyplot to manage your figure windows, but modify the
+GUI by accessing the underlying GTK widgets.
+"""
+
+import matplotlib
+matplotlib.use('GTK4Agg')  # or 'GTK4Cairo'
+import matplotlib.pyplot as plt
+
+import gi
+gi.require_version('Gtk', '4.0')
+from gi.repository import Gtk
+
+
+fig, ax = plt.subplots()
+ax.plot([1, 2, 3], 'ro-', label='easy as 1 2 3')
+ax.plot([1, 4, 9], 'gs--', label='easy as 1 2 3 squared')
+ax.legend()
+
+manager = fig.canvas.manager
+# you can access the window or vbox attributes this way
+toolbar = manager.toolbar
+vbox = manager.vbox
+
+# now let's add a button to the toolbar
+button = Gtk.Button(label='Click me')
+button.connect('clicked', lambda button: print('hi mom'))
+button.set_tooltip_text('Click me for fun and profit')
+toolbar.append(button)
+
+# now let's add a widget to the vbox
+label = Gtk.Label()
+label.set_markup('Drag mouse over axes for position')
+vbox.insert_child_after(label, fig.canvas)
+
+
+def update(event):
+    if event.xdata is None:
+        label.set_markup('Drag mouse over axes for position')
+    else:
+        label.set_markup(
+            f'<span color="#ef0000">x,y=({event.xdata}, {event.ydata})</span>')
+
+
+fig.canvas.mpl_connect('motion_notify_event', update)
+
+plt.show()
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -1098,8 +1098,8 @@ def use(backend, *, force=True):
         backend names, which are case-insensitive:
 
         - interactive backends:
-          GTK3Agg, GTK3Cairo, MacOSX, nbAgg, QtAgg, QtCairo,
-          TkAgg, TkCairo, WebAgg, WX, WXAgg, WXCairo, Qt5Agg, Qt5Cairo
+          GTK3Agg, GTK3Cairo, GTK4Agg, GTK4Cairo, MacOSX, nbAgg, QtAgg,
+          QtCairo, TkAgg, TkCairo, WebAgg, WX, WXAgg, WXCairo, Qt5Agg, Qt5Cairo
 
         - non-interactive backends:
           agg, cairo, pdf, pgf, ps, svg, template

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -101,6 +101,7 @@ def _safe_pyplot_import():
         backend_mapping = {
             'qt': 'qtagg',
             'gtk3': 'gtk3agg',
+            'gtk4': 'gtk4agg',
             'wx': 'wxagg',
             'tk': 'tkagg',
             'macosx': 'macosx',
@@ -1656,7 +1657,7 @@ class FigureCanvasBase:
         A high-level figure instance.
     """
 
-    # Set to one of {"qt", "gtk3", "wx", "tk", "macosx"} if an
+    # Set to one of {"qt", "gtk3", "gtk4", "wx", "tk", "macosx"} if an
     # interactive framework is required, or None otherwise.
     required_interactive_framework = None
 
@@ -1732,7 +1733,7 @@ def _fix_ipython_backend2gui(cls):
             # don't break on our side.
             return
         rif = getattr(cls, "required_interactive_framework", None)
-        backend2gui_rif = {"qt": "qt", "gtk3": "gtk3",
+        backend2gui_rif = {"qt": "qt", "gtk3": "gtk3", "gtk4": "gtk4",
                            "wx": "wx", "macosx": "osx"}.get(rif)
         if backend2gui_rif:
             if _is_non_interactive_terminal_ipython(ip):