list.sh

declare -A _list_obj

# $1 - variable name
function list.new() {
    _list_obj["$1"]=list
    _list_obj["$1:selected"]=0
    register_object $1 list
    _list_obj["$1:style"]=1
    _list_obj["$1:size"]=0
    _list_obj["$1:fixed_size"]=-1
    _list_obj["$1:prev_sx"]=0
    _list_obj["$1:prev_sy"]=0
    _list_obj["$1:prev_ex"]=0
    _list_obj["$1:prev_ey"]=0
    _list_obj["$1:fixed_layouts_size"]=0
    style.new $1
    style.new "$1.selected"
}

# $1 - list
# $2...$etc - items
# Set items to render inside of this list
# Resets selected item to 0
function list.set_items() {
    local i z=0

    while [ -n "${_list_obj["$1:items:$z"]}" ]; do
        unset  _list_obj["$1:items:$z"]
        z=$((z+1))
    done
    z=0
    for i in "${@:2}"; do
        _list_obj["$1:items:$z"]="${@:$((z+2)):1}"
        ((z+=1))
    done
    _list_obj["$1:selected"]=0
    _list_obj["$1:size"]=$z
}

# $1 - list
# $2 - item
# Adds item to end of list
function list.insert_item() {
    local i=${_list_obj["$1:size"]}
    _list_obj["$1:items:$i"]="$2"
    _list_obj["$1:size"]=$((i + 1))
}


# $1 - list
# $2 - positive, non zero, size in pixels to enable or disable (-1)
# Sets fixed size of layout for all components, resulting faster computation
function list.set_fixed_size() {
    _list_obj["$1:fixed_size"]=$2
}

# $1 - list
# $2 - selected position
# Guarantees that selecected component at given position gonna be visible
# If position greater than items size, it will set position to last item in list
function list.set_selected() {
    _list_obj["$1:selected"]=$2
}

# $1 - list
# $2, $3, ... - names of properties to enable, see style.set_style for more
function list.set_style() {
    style.set_style "$@"
}



# $1 - list
# $2, $3, ... - names of properties to enable, see style.set_style for more
# Style for selected item
function list.set_selected_style() {
    style.set_style "$1.selected" "${@:2}"
}

# $1 - list
# $2 - start x of layout
# $3 - start y of layout
# $4 - end x of layout
# $5 - end y of layout
function list._create_fixed_layouts() {
    if ! [ "${_list_obj["$1:prev_sx"]}" -eq "$2" ] || ! [ "${_list_obj["$1:prev_ex"]}" -eq "$4" ] || ! [ "${_list_obj["$1:prev_sy"]}" -eq "$3" ] || ! [ "${_list_obj["$1:prev_ey"]}" -eq "$5" ]; then
        list._delete_fixed_layouts $1
        local fixed_size=${_list_obj["$1:fixed_size"]}
        local free_space=$(( $5 - $3 + 1 ))
        local length=$((free_space / fixed_size ))
        local i=0
        local current_y=$3
        while [ "$current_y" -le "$5" ]; do

            layout.create_from_size ".$1.nested-$i" $2 $current_y $4 $((current_y + fixed_size - 1))
            ((i+=1))
            current_y=$((current_y + fixed_size))
        done
        _list_obj["$1:prev_sx"]=$2
        _list_obj["$1:prev_sy"]=$3
        _list_obj["$1:prev_ex"]=$4
        _list_obj["$1:prev_ey"]=$5
        _list_obj["$1:fixed_layouts_size"]=$i
    fi
}

# $1 - list
function list._delete_fixed_layouts() {
    local i=$((${_list_obj["$1:fixed_layouts_size"]} - 1))
    for ((i; i>=0; i--)) {
        layout.delete ".$1.nested-$i"
    }
}

# $1 - list
# $2 - layout
function list.draw() {
    local i=0
    local start_x start_y end_x end_y
    layout.get_rect $2 start_x start_y end_x end_y
    local current_y=$start_y
    
    
    style.apply_rect $1 $start_x $start_y $end_x $end_y
    if [ "${_list_obj["$1:size"]}" -ge 1 ]; then
        local break=0
        local selected=${_list_obj["$1:selected"]}
        if [ $selected -gt $((${_list_obj["$1:size"]} - 1)) ]; then
            selected=$((${_list_obj["$1:size"]} - 1))
        fi
        if [ ${_list_obj["$1:size"]} -eq 0  ]; then
            selected=-1
        fi
        local free_space=$((end_y - start_y + 1))
        local fixed_size=${_list_obj["$1:fixed_size"]}
        
        local starting_pos=0
        if [ "$fixed_size" -gt 0 ]; then
            list._create_fixed_layouts $1 $start_x $start_y $end_x $end_y
            starting_pos=$((selected + 1 - (free_space / fixed_size) ))
            if [ "$starting_pos" -lt 0 ]; then
                starting_pos=0
            fi
            local i=0
            while [ $starting_pos -le $((${_list_obj["$1:size"]} - 1)) ]; do
                local item=${_list_obj["$1:items:$starting_pos"]}
                local item_key=".$1.nested-$i"
                ((i+=1))
                if [ $starting_pos -eq $selected ]; then
                    style.apply_rect "$1.selected" $start_x $current_y $end_x $((current_y + fixed_size - 1))
                fi 
                object.draw $item $item_key
                current_y=$((current_y + fixed_size))
                if [ $current_y -ge $((end_y + 1)) ]; then
                    break
                fi
                ((starting_pos += 1))
            done
        else
            # Before selected
            for ((i=selected; i>=0; i-- )); do
                local ox oy;
                object.get_minimal_size ${_list_obj["$1:items:$i"]} $2 ox oy
                free_space=$((free_space - oy))
                if [ $free_space -lt 0 ]; then
                    starting_pos=$((i+1))
                    break
                fi
            done
            while [ $starting_pos -le $((${_list_obj["$1:size"]} - 1)) ]; do
                local item=${_list_obj["$1:items:$starting_pos"]}
                local item_key=".$1.nested-$item"
                local ox oy;
                if [ "$fixed_size" -gt 0 ]; then
                    oy=$fixed_size
                    ox=$fixed_size
                else
                    object.get_minimal_size $item $2 ox oy
                fi
                
                local max_y=$((current_y + oy - 1))
                if [ $max_y -ge $end_y ]; then
                    max_y=$end_y
                    break=1
                fi
                
                if [ $starting_pos -eq $selected ]; then
                    style.apply_rect "$1.selected" $start_x $current_y $end_x $max_y
                fi 
                layout.create_from_size $item_key $start_x $current_y $end_x $max_y
                object.draw $item $item_key
                layout.delete $item_key
            
                current_y=$((max_y + 1))
                if [ $break -eq 1 ]; then
                    break
                fi
                ((starting_pos += 1))
            done
        fi
    fi
}


# $1 - label
# $2 - layout within label will calculate its size
# $3 - variable name for x size
# $4 - variable name for y size
# Returns 0 0. You shoudn't rely on list implementation and instead define needed size in your components by yourself
function list.get_minimal_size() {
    export "$3=0"
    export "$4=0"
}

# $1 - variable name
# Deletes object
# After deletion of object its usage leads to undifined behaviour
# This list doesn't delete its items
function list.delete() {
    unset _list_obj["$1"]
    unset _list_obj["$1:selected"]
    unset _list_obj["$1:items"]
    unset _list_obj["$1:style"]
    unset _list_obj["$1:size"]
    unset _list_obj["$1:fixed_size"]
    list._delete_fixed_layouts $1
    unset _list_obj["$1:prev_sx"]
    unset _list_obj["$1:prev_sy"]
    unset _list_obj["$1:prev_ex"]
    unset _list_obj["$1:prev_ey"]
    local i=0
    while [ -n "${_list_obj["$1:items:$i"]}" ]; do
        unset ${_list_obj["$1:items:$i"]}
        ((i+=1))
    done
    style.delete $1
    style.delete "$1.selected"

    unregister_object $1
}