Merge pull request #29 from cid0rz/master

fix scrollbar and make text readonly

src/lib/components/terminal/terminal.py

@@ -5,7 +5,7 @@
 from sys import platform
 
 from threading import Thread
-from ..utils import AutoScrollbar
+from ..utils import AutoScrollbar, TextWithReadonly
 
 
 class Terminal(tk.Frame):
@@ -19,17 +19,18 @@ def __init__(self, master, *args, **kwargs):
         self.grid_columnconfigure(0, weight=1)
         self.grid_rowconfigure(0, weight=1)
 
-        self.terminal = tk.Text(
+        self.terminal = TextWithReadonly(
             self, wrap=tk.WORD, font=self.font, relief=tk.FLAT,
             fg="#333333", bg="#ffffff", padx=10, pady=10
         )
         self.terminal.grid(row=0, column=0, sticky=tk.NSEW)
 
-        self.terminal_scrollbar = AutoScrollbar(self.terminal)
-        self.terminal_scrollbar.grid(row=0, column=1, sticky=tk.NS)
+        self.terminal_scrollbar = AutoScrollbar(self)
+        self.terminal_scrollbar.grid(row=0, column=1, sticky='NSW')
 
+
         self.terminal.config(yscrollcommand=self.terminal_scrollbar.set)
-        self.terminal_scrollbar.config(command=self.terminal.yview)
+        self.terminal_scrollbar.config(command=self.terminal.yview, orient=tk.VERTICAL)
 
         self.line_start = 0
         self.alive = True
@@ -124,7 +125,7 @@ def write_loop(self):
                 self.alive = False
 
     def write(self, output):
-        self.terminal.insert(tk.END, output)
+        self.terminal.insert(tk.END, output, "readonly")
         self.terminal.see(tk.END)
         self.line_start += len(output)
 

src/lib/components/utils/__init__.py

@@ -1,3 +1,4 @@
 from .scrollbar import AutoScrollbar
 from .label import WrappingLabel
-from .filetype import FileType
+from .filetype import FileType
+from .text_with_readonly import TextWithReadonly

src/lib/components/utils/text_with_readonly.py

@@ -0,0 +1,66 @@
+import tkinter as tk
+
+class TextWithReadonly(tk.Text):
+    '''A text widget that doesn't permit inserts and deletes in regions tagged with "readonly"'''
+    def __init__(self, *args, **kwargs):
+        tk.Text.__init__(self, *args, **kwargs)
+
+        # this code creates a proxy that will intercept
+        # each actual insert and delete. 
+        self.tk.eval(WIDGET_PROXY)
+
+        # this code replaces the low level tk widget 
+        # with the proxy
+        widget = str(self)
+        self.tk.eval('''
+            rename {widget} _{widget}
+            interp alias {{}} ::{widget} {{}} widget_proxy _{widget} 
+        '''.format(widget=widget))
+
+WIDGET_PROXY = '''
+if {[llength [info commands widget_proxy]] == 0} {
+    # Tcl code to implement a text widget proxy that disallows
+    # insertions and deletions in regions marked with "readonly"
+    proc widget_proxy {actual_widget args} {
+        set command [lindex $args 0]
+        set args [lrange $args 1 end]
+        if {$command == "insert"} {
+            set index [lindex $args 0]
+            if [_is_readonly $actual_widget $index "$index+1c"] {
+                bell
+                return ""
+            }
+        }
+        if {$command == "delete"} {
+            foreach {index1 index2} $args {
+                if {[_is_readonly $actual_widget $index1 $index2]} {
+                    bell
+                    return ""
+                }
+            }
+        }
+        # if we passed the previous checks, allow the command to 
+        # run normally
+        $actual_widget $command {*}$args
+    }
+
+    proc _is_readonly {widget index1 index2} {
+        # return true if any text in the range between
+        # index1 and index2 has the tag "readonly"
+        set result false
+        if {$index2 eq ""} {set index2 "$index1+1c"}
+        # see if "readonly" is applied to any character in the
+        # range. There's probably a more efficient way to do this, but
+        # this is Good Enough
+        for {set index $index1} \
+            {[$widget compare $index < $index2]} \
+            {set index [$widget index "$index+1c"]} {
+                if {"readonly" in [$widget tag names $index]} {
+                    set result true
+                    break
+                }
+            }
+        return $result
+    }
+}
+'''