Handheld electronic device and associated method enabling text input in a language employing non-roman characters

Abstract

A handheld device includes a plurality of input members, a first set of which each have a Roman character assigned thereto, a least some of which have a first non-Roman, second non-Roman character, and third non-Roman characters assigned thereto. The device is switchable between first and second modes. In the first mode, each Roman character may be input in response to actuation of the input member to which it is assigned, and in the second mode, each first non-Roman character may be input in response to a first type of actuation of the input member to which it is assigned, each second non-Roman character may input in response to a second type of actuation of the input member to which it is assigned, and each third non-Roman character may be input in response to a third type of actuation of the input member to which it is assigned.

1 .- 6 . (canceled) 
     
     
         7 . A handheld electronic device comprising;
 at least one processor;   an input apparatus comprising a plurality of input keys, a first set of the input keys each having a Roman character assigned thereto, at least some of the input keys in the first set of the input keys having a first non-Roman character, a second non-Roman character, and a third non-Roman character assigned thereto; and   a memory having stored therein a number of routines which, when executed on the processor, cause the handheld electronic device to be selectively switchable between: (i) a Roman character input mode, and (ii) a non-Roman character input mode, wherein   in said Roman character input mode, each said Roman characters may be selected and input into said processor in response to selection of the input key to which it is assigned, and   in said non-Roman character input mode,
 said processor determines whether the handheld electronic device is in a shift mode after switching to the non-Roman character input mode, and 
 responsive to determining that the handheld electronic device is not in the shift mode, each first non-Roman character may be selected in response to a first type of selection of the input key to which it is assigned, each second non-Roman character may be selected in response to a second type of selection of the input key to which it is assigned, and 
 responsive to determining that handheld electronic device is in the shift mode, each third non-Roman character may be selected in response to a third type of selection of the input key to which it is assigned. 
   
     
     
         8 . The handheld electronic device according to  claim 7 , wherein said first type of selection comprises a single selection of the input key and said second type of selection comprises a first selection of the input key followed by a second selection of the input key within a predetermined time frame. 
     
     
         9 . The handheld electronic device according to  claim 8 , wherein said third type of selection comprises a single selection of the input key when said handheld electronic device is in said shift mode. 
     
     
         10 . The handheld electronic device according to  claim 7 , wherein said non-Roman characters are from a first language having one or more rules that govern permissible character sequences, said routines, when executed on the processor, further cause the processor to:
 in response to an selection of a first one of the input keys, display on an output apparatus a first one of the non-Roman characters that is assigned to the first one of the input keys; and   based on said one or more rules that govern permissible character sequences in the first language, prevent display on said output apparatus of a second one of the non-Roman characters in response to an selection of a second one of the input keys having the second one of the non-Roman characters assigned thereto immediately following said selection of said first one of the input keys.   
     
     
         11 . The handheld electronic device according to  claim 10 , wherein said routines, when executed on the processor, further cause the processor to display a third one of the non-Roman characters provided on said second one of the input keys and different than said second one of the non-Roman characters in response to said selection of said second one of the input keys. 
     
     
         12 . The handheld electronic device according to  claim 7 , wherein each said first non-Roman character, said second non-Roman character, and said third non-Roman character is a Thai character. 
     
     
         13 . The handheld electronic device according to  claim 7 , wherein upon the second type of selection of the input key to which it is assigned, the first non-Roman character corresponding to the first type of selection of the input key to which it is assigned, is displayed and highlighted, prior to the second non-Roman character corresponding to the second type of selection is displayed. 
     
     
         14 . The handheld electronic device according to  claim 7 , wherein the handheld electronic device further comprises a keyboard, and the first non-Roman character, the second non-Roman character, and the third non-Roman character are displayed on a same key of the keyboard. 
     
     
         15 . A method for processing input from a handheld electronic device comprising:
 determining whether the handheld electronic device is in a shift mode after switching from a Roman character input mode to a non-Roman character input mode, wherein the handheld electronic device is selectively switchable between said Roman character input mode and said non-Roman character input mode, and in said Roman character input mode, a Roman character may be selected and in response to selection of an input key to which it is assigned;   responsive to determining that the handheld electronic device is not in the shift mode, selecting a first non-Roman character in response to a first type of selection of the input key to which it is assigned, and selecting a second non-Roman character in response to a second type of selection of the input key to which it is assigned; and   responsive to determining that handheld electronic device is in the shift mode, selecting a third non-Roman character in response to a third type of selection of the input key to which it is assigned.   
     
     
         16 . The method according to  claim 15 , wherein said first type of selection comprises a single selection of the input key and said second type of selection comprises a first selection of the input key followed by a second selection of the input key within a predetermined time frame. 
     
     
         17 . The method according to  claim 16 , wherein said third type of selection comprises a single selection of the input key when said handheld electronic device is in said shift mode. 
     
     
         18 . The method according to  claim 15 , further comprising:
 in response to an selection of a first one of the input keys, displaying on an output apparatus a first one of the non-Roman characters that is assigned to the first one of the input keys; and   based on said one or more rules that govern permissible character sequences in the first language, preventing display on said output apparatus of a second one of the non-Roman characters in response to an selection of a second one of the input keys having the second one of the non-Roman characters assigned thereto immediately following said selection of said first one of the input keys,   wherein said non-Roman characters are from a first language having one or more rules that govern permissible character sequences.   
     
     
         19 . The method according to  claim 18 , further comprising displaying a third one of the non-Roman characters provided on said second one of the input keys and different than said second one of the non-Roman characters in response to said selection of said second one of the input keys. 
     
     
         20 . The method according to  claim 15 , wherein each said first non-Roman character, said second non-Roman character, and said third non-Roman character is a Thai character. 
     
     
         21 . The method according to  claim 15 , wherein upon the second type of selection of the input key to which it is assigned, the first non-Roman character corresponding to the first type of selection of the input key to which it is assigned, is displayed and highlighted, prior to the second non-Roman character corresponding to the second type of selection is displayed. 
     
     
         22 . The method according to  claim 15 , wherein the handheld electronic device further comprises a keyboard, and the first non-Roman character, the second non-Roman character, and the third non-Roman character are displayed on a same key of the keyboard.