gui: Conform to $ret and $result conventions.

Unlike the rest of gsu, the functions of the gui module did not follow
the rule that functions should always set $ret to indicate error or
success, and $result to either the result of the function (if any)
or to an error context string. This commit makes all functions of
the gui module conform to this rule.

This patch also improves the error handling of _gsu_menu(). This
function should distinguish between three cases, according to the
exit code of dialog(1): OK (user selected the OK button), Cancel
(user pressed the escape key or selected the Cancel button), and error
(dialog(1) failed to execute or returned unsuccessfully).

The old code does not distinguish between the last two cases. Hence one
could not exit the application by pressing CTRL+C from a menu. This
patch changes _gsu_menu() to look more carefully at the exit code of
dialog(1) to tell apart the "error" case and the "cancel" case.

diff --git a/common b/common
index eaa5751b43a9133fba3e497b5d45babe1e46b0e9..cd07252fa1d6917905b41d868fcdbcb67d54f89b 100644 (file)
--- a/common
+++ b/common
@@ -15,6 +15,9 @@ E_GSU_BAD_ARG_COUNT           invalid number of arguments
 E_GSU_EDITOR                   failed to execute editor
 E_GSU_MKDIR                    failed to create directory
 E_GSU_GETOPTS                  getopts error
+E_GSU_DIALOG                   dialog error
+E_GSU_MKTEMP                   mktemp error
+E_GSU_MENU_TREE                        invalid menu tree
 $gsu_errors
 "
        local a b i=0

diff --git a/gui b/gui
index 336d1547ad6366af9dd3cb481cd0a29b87d08167..3c89567cceae816d58cd9bd438ce0fe2d8cf2410 100644 (file)
--- a/gui
+++ b/gui
@@ -29,15 +29,25 @@ gsu_inputbox()
        _get_geometry
        g="$result"
        result="$(dialog --inputbox "$text" $g "$init" 3>&1 1>&2 2>&3 3>&-)"
-       ret="$?"
+       if (($? != 0)); then
+               ret=-$E_GSU_DIALOG
+               result='inputbox'
+               return
+       fi
+       ret=$GSU_SUCCESS
 }
 
 gsu_textbox()
 {
-       local file="$1"
+       local g file="$1"
 
        _get_geometry
-       dialog --textbox "$file" $result
+       g="$result"
+
+       ret=-$E_GSU_DIALOG
+       result='textbox'
+       dialog --textbox "$file" $g || return
+       ret=$GSU_SUCCESS
 }
 
 # dialog segfaults if message is too long. Hence we always use a temporary file
@@ -46,12 +56,13 @@ gsu_msgbox()
        local tmp="$(mktemp gsu_msgbox.XXXXXXXXXX)"
 
        if (($? != 0)); then
-               dialog --msgbox "mktemp error" 0 0
+               ret=-$E_GSU_MKTEMP
+               result='temp file for textbox'
                return
        fi
        echo "$1" > "$tmp"
        gsu_textbox "$tmp"
-       rm -f "$tmp"
+       rm -f "$tmp" # ignore errors
 }
 
 _gsu_menu()
@@ -67,7 +78,13 @@ _gsu_menu()
                opts+=" $i $num"
        done
        result="$(dialog --menu "$gsu_banner_txt ($header)" $opts 3>&1 1>&2 2>&3 3>&-)"
-       ret="$?"
+       case $? in
+       0) ret=$GSU_SUCCESS;;
+       1) ret=1;; # cancelled
+       *)
+               result="menu error $ret"
+               ret=-$E_GSU_DIALOG
+       esac
 }
 
 _get_level()
@@ -81,7 +98,9 @@ _get_subtree()
        local tree="$1" root="${2%/}"
        local first TAB='       '
 
-       first="$(grep -n "$TAB\{1,\}$root/" <<< "$tree")"
+       ret=-$E_GSU_MENU_TREE
+       result="subtree grep failed"
+       first="$(grep -n "$TAB\{1,\}$root/" <<< "$tree")" || return
        [[ -z "$first" ]] && return
 
        line_num="${first%%:*}"
@@ -92,7 +111,12 @@ _get_subtree()
        result="$(sed -e "1,${line_num}d;" <<< "$tree" \
                | sed -e "/^$TAB\{1,$level\}$_gsu_node_name_pattern/,\$d" \
                | sed -e "/^$TAB\{$(($level + 2))\}/d")"
-       ret="$level"
+       if (($? != 0)); then
+               ret=-$E_GSU_MENU_TREE
+               result="sed command for subtree $root failed"
+               return
+       fi
+       ret=$GSU_SUCCESS
 }
 
 _get_root_nodes()
@@ -100,6 +124,12 @@ _get_root_nodes()
        local tree="$1" TAB='   '
 
        result="$(grep "^${TAB}${_gsu_node_name_pattern}" <<< "$tree")"
+       if (($? != 0)); then
+               ret=-$E_GSU_MENU_TREE
+               result="root node grep failed"
+               return
+       fi
+       ret=$GSU_SUCCESS
 }
 
 _browse()
@@ -109,13 +139,15 @@ _browse()
 
        while :; do
                _gsu_menu "$header" "$subtree"
-               (($ret != 0)) && return
-               [[ -z "$result" ]] && return
+               (($ret < 0)) && return
+               [[ -z "$result" ]] && return # menu was cancelled
                if [[ "${result%/}" != "$result" ]]; then
                        old_header="$header"
                        header="$result"
                        _get_subtree "$tree" "$header"
+                       (($ret < 0)) && return
                        _browse "$header" "$tree" "$result"
+                       (($ret < 0)) && return
                        header="$old_header"
                        continue
                fi