[input] Invoke onChange() on text change.

input.lua

@@ -85,6 +85,8 @@ function Input:textinput(text)
 
         self.text = table.concat {a, text, b}
         self.cursor = self.cursor + utf8.len(text)
+
+        self:onChange(self.text)
     end
 end
 
@@ -100,21 +102,22 @@ function Input:keypressed(key, code, isrepeat)
     end
 
     if self.candidate.length == 0 then
-        if key == 'backspace' then
+        if key == 'backspace' and self.cursor > 1 then
             local a,b = split(self.text, self.cursor)
 
             self.text = table.concat { split(a, utf8.len(a)), b }
-            self.cursor = math.max(1, self.cursor-1)
+            self.cursor = self.cursor-1
 
-        elseif key == 'delete' then
+            self:onChange(self.text)
+        elseif key == 'delete' and self.cursor ~= utf8.len(self.text)+1 then
             local a,b = split(self.text, self.cursor)
             local _,b = split(b, 2)
 
             self.text = table.concat { a, b }
 
+            self:onChange(self.text)
         elseif key == 'left' then
-            self.cursor = math.max(0, self.cursor-1)
-
+            self.cursor = math.max(1, self.cursor-1)
         elseif key == 'right' then
             self.cursor = math.min(utf8.len(self.text)+1, self.cursor+1)
         end