#344 select all and improved input fields

graphics/core.lua

@@ -111,4 +111,182 @@ function core.pipe(x1, y1, x2, y2, color, thin, align_tr)
     }
 end
 
+-- Interactive Field Manager
+
+---@param e graphics_base
+---@param max_len any
+---@param fg_bg any
+---@param dis_fg_bg any
+function core.new_ifield(e, max_len, fg_bg, dis_fg_bg)
+    local self = {
+        frame_start = 1,
+        visible_text = e.value,
+        cursor_pos = string.len(e.value) + 1,
+        selected_all = false
+    }
+
+    -- update visible text
+    local function _update_visible()
+        self.visible_text = string.sub(e.value, self.frame_start, self.frame_start + math.min(string.len(e.value), e.frame.w) - 1)
+    end
+
+    -- try shifting frame left
+    local function _try_lshift()
+        if self.frame_start > 1 then
+            self.frame_start = self.frame_start - 1
+            return true
+        end
+    end
+
+    -- try shifting frame right
+    local function _try_rshift()
+        if (self.frame_start + e.frame.w - 1) < string.len(e.value) then
+            self.frame_start = self.frame_start + 1
+            return true
+        end
+    end
+
+    ---@class ifield
+    local public = {}
+
+    -- show the field
+    function public.show()
+        _update_visible()
+
+        if e.enabled then
+            e.w_set_bkg(fg_bg.bkg)
+            e.w_set_fgd(fg_bg.fgd)
+        else
+            e.w_set_bkg(dis_fg_bg.bkg)
+            e.w_set_fgd(dis_fg_bg.fgd)
+        end
+
+        -- clear and print
+        e.w_set_cur(1, 1)
+        e.w_write(string.rep(" ", e.frame.w))
+        e.w_set_cur(1, 1)
+
+        if e.is_focused() and e.enabled then
+            -- write text with cursor
+            if self.selected_all then
+                e.w_set_bkg(fg_bg.fgd)
+                e.w_set_fgd(fg_bg.bkg)
+                e.w_write(self.visible_text)
+            elseif self.cursor_pos == (string.len(self.visible_text) + 1) then
+                -- write text with cursor at the end, no need to blit
+                e.w_write(self.visible_text)
+                e.w_set_fgd(colors.lightGray)
+                e.w_write("_")
+            else
+                local a, b = "", ""
+
+                if self.cursor_pos <= string.len(self.visible_text) then
+                    a = fg_bg.blit_bkg
+                    b = fg_bg.blit_fgd
+                end
+
+                local b_fgd = string.rep(fg_bg.blit_fgd, self.cursor_pos - 1) .. a .. string.rep(fg_bg.blit_fgd, string.len(self.visible_text) - self.cursor_pos)
+                local b_bkg = string.rep(fg_bg.blit_bkg, self.cursor_pos - 1) .. b .. string.rep(fg_bg.blit_bkg, string.len(self.visible_text) - self.cursor_pos)
+
+                e.w_blit(self.visible_text, b_fgd, b_bkg)
+            end
+        else
+            self.selected_all = false
+
+            -- write text without cursor
+            e.w_write(self.visible_text)
+        end
+    end
+
+    -- move cursor to x
+    ---@param x integer
+    function public.move_cursor(x)
+        self.selected_all = false
+        self.cursor_pos = math.min(x, string.len(self.visible_text) + 1)
+        public.show()
+    end
+
+    -- select all text
+    function public.select_all()
+        self.selected_all = true
+        public.show()
+    end
+
+    -- set field value
+    ---@param val string
+    function public.set_value(val)
+        e.value = string.sub(val, 1, math.min(max_len, string.len(val)))
+
+        self.selected_all = false
+        self.frame_start = 1 + math.max(0, string.len(val) - e.frame.w)
+
+        _update_visible()
+        self.cursor_pos = string.len(self.visible_text) + 1
+
+        public.show()
+    end
+
+    -- try to insert a character if there is space
+    ---@param char string
+    function public.try_insert_char(char)
+        -- limit length
+        if string.len(e.value) >= max_len then return end
+
+        -- replace if selected all, insert otherwise
+        if self.selected_all then
+            self.selected_all = false
+            self.cursor_pos = 2
+            self.frame_start = 1
+
+            e.value = char
+            public.show()
+        else
+            e.value = string.sub(e.value, 1, self.frame_start + self.cursor_pos - 2) .. char .. string.sub(e.value, self.frame_start + self.cursor_pos - 1, string.len(e.value))
+            _update_visible()
+
+            if self.cursor_pos <= string.len(self.visible_text) then
+                self.cursor_pos = self.cursor_pos + 1
+                public.show()
+            elseif _try_rshift() then public.show() end
+        end
+    end
+
+    -- remove charcter before cursor if there is anything to remove, or delete all if selected all
+    function public.backspace()
+        if self.selected_all then
+            self.selected_all = false
+            e.value = ""
+            self.cursor_pos = 1
+            self.frame_start = 1
+            public.show()
+        else
+            if self.frame_start + self.cursor_pos > 2 then
+                e.value = string.sub(e.value, 1, self.frame_start + self.cursor_pos - 3) .. string.sub(e.value, self.frame_start + self.cursor_pos - 1, string.len(e.value))
+                if self.cursor_pos > 1 then
+                    self.cursor_pos = self.cursor_pos - 1
+                    public.show()
+                elseif _try_lshift() then public.show() end
+            end
+        end
+    end
+
+    -- move cursor left by one
+    function public.nav_left()
+        if self.cursor_pos > 1 then
+            self.cursor_pos = self.cursor_pos - 1
+            public.show()
+        elseif _try_lshift() then public.show() end
+    end
+
+    -- move cursor right by one
+    function public.nav_right()
+        if self.cursor_pos <= string.len(self.visible_text) then
+            self.cursor_pos = self.cursor_pos + 1
+            public.show()
+        elseif _try_rshift() then public.show() end
+    end
+
+    return public
+end
+
 return core