Issue #27380: IDLE: add base Query dialog, with ttk widgets and subclass

SectionName.  These split class GetCfgSectionNameDialog from
configSectionNameDialog.py, temporarily renamed config_sec.py in 3.7.9a2.
More Query subclasses are planned.

1 files changed, 148 insertions, 0 deletions

diff --git a/Lib/idlelib/query.py b/Lib/idlelib/query.py
new file mode 100644
index 0000000..e3937a1
--- /dev/null
+++ b/Lib/idlelib/query.py
@@ -0,0 +1,148 @@
+"""
+Dialogs that query users and verify the answer before accepting.
+Use ttk widgets, limiting use to tcl/tk 8.5+, as in IDLE 3.6+.
+
+Query is the generic base class for a popup dialog.
+The user must either enter a valid answer or close the dialog.
+Entries are validated when <Return> is entered or [Ok] is clicked.
+Entries are ignored when [Cancel] or [X] are clicked.
+The 'return value' is .result set to either a valid answer or None.
+
+Subclass SectionName gets a name for a new config file section.
+Configdialog uses it for new highlight theme and keybinding set names.
+"""
+# Query and Section name result from splitting GetCfgSectionNameDialog
+# of configSectionNameDialog.py (temporarily config_sec.py) into
+# generic and specific parts.
+
+from tkinter import FALSE, TRUE, Toplevel
+from tkinter.messagebox import showerror
+from tkinter.ttk import Frame, Button, Entry, Label
+
+class Query(Toplevel):
+    """Base class for getting verified answer from a user.
+
+    For this base class, accept any non-blank string.
+    """
+    def __init__(self, parent, title, message,
+                 *, _htest=False, _utest=False):  # Call from override.
+        """Create popup, do not return until tk widget destroyed.
+
+        Additional subclass init must be done before calling this.
+
+        title - string, title of popup dialog
+        message - string, informational message to display
+        _htest - bool, change box location when running htest
+        _utest - bool, leave window hidden and not modal
+        """
+        Toplevel.__init__(self, parent)
+        self.configure(borderwidth=5)
+        self.resizable(height=FALSE, width=FALSE)
+        self.title(title)
+        self.transient(parent)
+        self.grab_set()
+        self.bind('<Key-Return>', self.ok)
+        self.protocol("WM_DELETE_WINDOW", self.cancel)
+        self.parent = parent
+        self.message = message
+        self.create_widgets()
+        self.update_idletasks()
+        #needs to be done here so that the winfo_reqwidth is valid
+        self.withdraw()  # Hide while configuring, especially geometry.
+        self.geometry(
+                "+%d+%d" % (
+                    parent.winfo_rootx() +
+                    (parent.winfo_width()/2 - self.winfo_reqwidth()/2),
+                    parent.winfo_rooty() +
+                    ((parent.winfo_height()/2 - self.winfo_reqheight()/2)
+                    if not _htest else 150)
+                ) )  #centre dialog over parent (or below htest box)
+        if not _utest:
+            self.deiconify()  #geometry set, unhide
+            self.wait_window()
+
+    def create_widgets(self):  # Call from override, if any.
+        frame = Frame(self, borderwidth=2, relief='sunken', )
+        label = Label(frame, anchor='w', justify='left',
+                    text=self.message)
+        self.entry = Entry(frame, width=30)  # Bind name for entry_ok.
+        self.entry.focus_set()
+
+        buttons = Frame(self)  # Bind buttons for invoke in unittest.
+        self.button_ok = Button(buttons, text='Ok',
+                width=8, command=self.ok)
+        self.button_cancel = Button(buttons, text='Cancel',
+                width=8, command=self.cancel)
+
+        frame.pack(side='top', expand=TRUE, fill='both')
+        label.pack(padx=5, pady=5)
+        self.entry.pack(padx=5, pady=5)
+        buttons.pack(side='bottom')
+        self.button_ok.pack(side='left', padx=5)
+        self.button_cancel.pack(side='right', padx=5)
+
+    def entry_ok(self):  # Usually replace.
+        "Check that entry not blank."
+        entry = self.entry.get().strip()
+        if not entry:
+            showerror(title='Entry Error',
+                    message='Blank line.', parent=self)
+        return entry
+
+    def ok(self, event=None):  # Do not replace.
+        '''If entry is valid, bind it to 'result' and destroy tk widget.
+
+        Otherwise leave dialog open for user to correct entry or cancel.
+        '''
+        entry = self.entry_ok()
+        if entry:
+            self.result = entry
+            self.destroy()
+        else:
+            # [Ok] (but not <Return>) moves focus.  Move it back.
+            self.entry.focus_set()
+
+    def cancel(self, event=None):  # Do not replace.
+        "Set dialog result to None and destroy tk widget."
+        self.result = None
+        self.destroy()
+
+
+class SectionName(Query):
+    "Get a name for a config file section name."
+
+    def __init__(self, parent, title, message, used_names,
+                 *, _htest=False, _utest=False):
+        "used_names - collection of strings already in use"
+
+        self.used_names = used_names
+        Query.__init__(self, parent, title, message,
+                 _htest=_htest, _utest=_utest)
+        # This call does ot return until tk widget is destroyed.
+
+    def entry_ok(self):
+        '''Stripping entered name, check that it is a  sensible
+        ConfigParser file section name. Return it if it is, '' if not.
+        '''
+        name = self.entry.get().strip()
+        if not name:
+            showerror(title='Name Error',
+                    message='No name specified.', parent=self)
+        elif len(name)>30:
+            showerror(title='Name Error',
+                    message='Name too long. It should be no more than '+
+                    '30 characters.', parent=self)
+            name = ''
+        elif name in self.used_names:
+            showerror(title='Name Error',
+                    message='This name is already in use.', parent=self)
+            name = ''
+        return name
+
+
+if __name__ == '__main__':
+    import unittest
+    unittest.main('idlelib.idle_test.test_query', verbosity=2, exit=False)
+
+    from idlelib.idle_test.htest import run
+    run(Query)