Adding credits panel.

Author: Chad Juliano

src/biw-credits.sh

@@ -0,0 +1,373 @@
+##
+# BIW-TOOLS - Bash Inline Widget Tools
+# Copyright 2017 by Chad Juliano
+# 
+# Licensed under GNU Lesser General Public License v3.0 only. Some rights
+# reserved. See LICENSE.
+##
+
+# constants
+declare -r CRED_ANIMATE_DELAY=0.03
+declare -ir CRED_CURSOR_PERIOD=14
+declare -ir CRED_CURSOR_MAX=$((CRED_CURSOR_PERIOD * 3))
+
+# panel layout
+declare -i cred_height
+declare -i cred_width
+declare -i cred_row_pos
+
+declare -a cred_line_data
+declare -i cred_line_data_size
+
+declare -i cred_canvas_row_pos
+declare -i cred_canvas_col_pos
+declare -i cred_canvas_width
+declare -i cred_canvas_height
+
+declare -a cred_color_map
+declare -i cred_color_map_size
+declare -a cred_alpha_map
+
+function fn_cred_show()
+{
+    # Panel geometry
+    cred_height=$((BIW_PANEL_HEIGHT - HMENU_HEIGHT))
+    cred_width=$BIW_PANEL_WIDTH
+    cred_row_pos=$HMENU_HEIGHT
+
+    # geometry of drawing canvas
+    cred_canvas_row_pos=$cred_row_pos
+    cred_canvas_col_pos=1
+    cred_canvas_width=$((cred_width - 2))
+    cred_canvas_height=$((cred_height - 1))
+
+    cred_alpha_map[cred_canvas_width]=0
+
+    fn_cred_blank_panel
+    fn_cred_load_data
+    fn_generate_color_map
+    fn_cred_print_data
+
+    # if animation was canceled then we get a non-zero status
+    return $?
+}
+
+function fn_generate_color_map()
+{
+    fn_theme_get_sgr $SGR_ATTR_FG $TATTR_TEXT
+    _sgr_text_color=$(($? - SGR_ATTR_FG))
+
+    cred_color_map=(
+        [1]=$_sgr_text_color
+        [2]=$SGR_COL_YELLOW
+        [3]=$SGR_COL_YELLOW
+        [4]=$SGR_COL_YELLOW
+        [5]=$SGR_COL_YELLOW
+        [6]=$SGR_COL_YELLOW
+        [7]=$SGR_COL_YELLOW
+        [8]=$SGR_COL_YELLOW
+        [9]=$SGR_COL_YELLOW
+        [10]=$SGR_COL_YELLOW
+        [11]=$SGR_COL_YELLOW
+        [12]=$SGR_COL_YELLOW
+    )
+
+    cred_color_map_size=${#cred_color_map[@]}
+}
+
+function fn_cred_print_data()
+{
+    local -i _line_idx
+    local -i _persist_cursor=0
+
+    for((_line_idx = 0; _line_idx < cred_canvas_height; _line_idx++))
+    do
+        local _line_val="${cred_line_data[_line_idx]:-}"
+        fn_cred_canvas_set_cursor $_line_idx 0
+
+        if((_line_idx == (cred_canvas_height - 1)))
+        then
+            _persist_cursor=1
+        fi
+
+        if ! fn_cred_print_line "${_line_val}" $_persist_cursor
+        then
+            # cancel by user input
+            return 1
+        fi
+    done
+
+    return 0
+}
+
+function fn_cred_print_line()
+{
+    local _line_val=$1
+    local -i _persist_cursor=$2
+
+    local -i _line_width=${#_line_val}
+
+    if((_line_width == 0))
+    then
+        return 0
+    fi
+
+    # init zero valued array
+    local _char_idx
+    for((_char_idx=0; _char_idx < _line_width; _char_idx++))
+    do
+        cred_alpha_map[_char_idx]=0
+    done
+
+    # set the cursor in a position that will center the text
+    local -i _line_start=$(((cred_canvas_width - _line_width) / 2))
+
+    # sprite indicators
+    local -i _text_active=1
+    local -i _alpha_active=1
+    local -i _cursor_active=0
+
+    local -i _char_idx=0
+    local -i _cursor_counter=$CRED_CURSOR_MAX
+    local _result_char
+
+    # start main animation loop
+    while fn_biw_process_key _result_char $CRED_ANIMATE_DELAY
+    do
+        # activate chars in alpha map
+        if((_text_active))
+        then
+            if ! fn_cred_animate_text $_char_idx $_line_width
+            then
+                _text_active=0
+                _cursor_active=1
+            fi
+            ((_char_idx++))
+        fi
+
+        # process alpha map
+        if((_alpha_active))
+        then
+            if ! fn_cred_print_alpha "$_line_val" $_line_start
+            then
+                _alpha_active=0
+            fi
+        fi
+
+        # process cursor
+        if((_cursor_active))
+        then
+            if ! fn_cred_animate_cursor $((_line_start + _line_width))
+            then
+                _cursor_active=$_persist_cursor
+            fi
+            ((_cursor_counter--))
+        fi
+
+        if((!_alpha_active && !_cursor_active))
+        then
+            # nothing left for fn_cred_print_alpha
+            # normal termination
+            return 0
+        fi
+    done
+
+    # cancel by user input
+    return 1
+}
+
+function fn_cred_animate_text()
+{
+    local -i _char_idx=$1
+    local -i _line_width=$2
+
+    # add characters to the alpha map
+    if((_char_idx < _line_width))
+    then
+        cred_alpha_map[_char_idx]=${#cred_color_map[@]}
+    else
+        return 1
+    fi
+
+    return 0
+}
+
+function fn_cred_animate_cursor()
+{
+    local -i _cursor_pos=$1
+
+    if(( _cursor_counter % (CRED_CURSOR_PERIOD / 2) ))
+    then
+        # nothing to do
+        return 0
+    fi
+
+    fn_biw_set_col_pos $_cursor_pos
+
+    local _sgr_color=${cred_color_map[cred_color_map_size - 1]}
+    fn_sgr_set $((SGR_ATTR_FG + _sgr_color))
+
+    if((_cursor_counter <= 0))
+    then
+        # terminate
+        _cursor_counter=$((CRED_CURSOR_MAX + 1))
+        fn_sgr_print " "
+        return 1
+    fi
+
+    local _sgr_char=" "
+    if(( !(_cursor_counter % CRED_CURSOR_PERIOD) ))
+    then
+        _sgr_char="_"
+    fi
+
+    fn_sgr_print "$_sgr_char"
+
+    return 0
+}
+
+function fn_cred_print_alpha()
+{
+    local _line_val=$1
+    local -i _line_start=$2
+    local -i _line_width=${#_line_val}
+
+    local -i _alpha_idx
+    local -i _alpha_val
+    local -i _alpha_start=-1
+
+    # find the first nonzero alpha value
+    for((_alpha_idx=0; _alpha_idx < $_line_width; _alpha_idx++))
+    do
+        _alpha_val=${cred_alpha_map[_alpha_idx]}
+
+        if((_alpha_val > 0))
+        then
+            _alpha_start=_alpha_idx
+            break
+        fi
+    done
+
+    if((_alpha_start < 0))
+    then
+        # nothing to do
+        return 1
+    fi
+
+    fn_biw_set_col_pos $((_line_start + _alpha_start))
+
+    fn_sgr_seq_start
+
+    local _char_val
+    local -i _alpha_color
+
+    for((_alpha_idx=_alpha_start; _alpha_idx < $_line_width; _alpha_idx++))
+    do
+        _alpha_val=${cred_alpha_map[_alpha_idx]}
+        if((_alpha_val == 0))
+        then
+            # we hit the end
+            break
+        fi
+
+        _alpha_color=${cred_color_map[_alpha_val]}
+        fn_sgr_set $((SGR_ATTR_FG + _alpha_color))
+
+        _char_val=${_line_val:_alpha_idx:1}
+        fn_sgr_print "${_char_val}"
+
+        # each value in the alpha list needs to get decremented
+        cred_alpha_map[_alpha_idx]=$((_alpha_val - 1))
+    done
+
+    # this will flush the buffer and print the output
+    fn_sgr_seq_flush
+
+    return 0
+}
+
+function fn_cred_load_data()
+{
+    mapfile -n${cred_height} -t cred_line_data <<-EOM
+
+BIW - Bash Inline Widgets
+Copyright 2017 by Chad Juliano
+[email protected]
+
+Find it at:
+https://github.com/chadj2/biw-tools
+EOM
+
+    cred_line_data_size=${#cred_line_data[*]}
+}
+
+function fn_cred_canvas_set_cursor()
+{
+    local -i _row_pos=$1
+    local -i _col_pos=$2
+    fn_biw_set_cursor_pos \
+        $((cred_canvas_row_pos + _row_pos)) \
+        $((cred_canvas_col_pos + _col_pos))
+
+    fn_theme_set_bg_attr $TATTR_BG_INACTIVE
+}
+
+function fn_cred_blank_panel()
+{
+    local -i _line_idx
+
+    for((_line_idx = 0; _line_idx < cred_height; _line_idx++))
+    do
+        local -i _row_pos=$((cred_row_pos + _line_idx))
+        fn_biw_set_cursor_pos $_row_pos 0
+
+        fn_sgr_seq_start
+        fn_theme_set_bg_attr $TATTR_BG_INACTIVE
+
+        if((_line_idx < cred_canvas_height))
+        then
+            fn_cred_blank_line
+        else
+            fn_cred_draw_bottom
+        fi
+        fn_sgr_seq_flush
+    done
+}
+
+function fn_cred_blank_line()
+{
+    local _line_val
+    fn_cred_repeat_chars "_line_val" $cred_canvas_width
+    fn_sgr_print $CSI_CHAR_LINE_VERT
+    fn_sgr_print "$_line_val"
+    fn_sgr_print $CSI_CHAR_LINE_VERT
+}
+
+function fn_cred_draw_bottom()
+{
+    local _dsc_start=$'\e(0'
+    local _dsc_horiz_line=$'\x71'
+    local _dsc_end=$'\e(B'
+
+    # draw bottom box
+    fn_sgr_print $CSI_CHAR_LINE_BL
+    fn_sgr_print $_dsc_start
+
+    local _bottom_line
+    fn_cred_repeat_chars "_bottom_line" $cred_canvas_width $_dsc_horiz_line
+    fn_sgr_print $_bottom_line
+
+    fn_sgr_print $CSI_CHAR_LINE_BR
+    fn_sgr_print $_dsc_end
+}
+
+function fn_cred_repeat_chars()
+{
+    local _var_name=$1
+    local -i _pad_width=$2
+    local _pad_char=${3:- }
+
+    printf -v $_var_name '%*s' $_pad_width
+    local _result_val=${!_var_name// /${_pad_char}}
+    eval $_var_name='$_result_val'
+}