[PATCH 1/8] video: Add cursor support for DM_VIDEO consoles

[Simon Glass]

Hi Andre,

On Sun, 9 Jan 2022 at 17:57, Andre Przywara <andre.przywara at arm.com> wrote:
>
> So far the DM_VIDEO console is completely lacking any cursor, which makes
> typing and correcting quite irritating.
>
> Add a simple cursor display by writing a SPACE glyph in the background
> colour to the next character position on the screen. Any typed character
> will naturally overwrite it, so we need to only explicitly clear it if
> the next character will appear somewhere else (newline, backspace).
>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  drivers/video/console_normal.c    |  1 +
>  drivers/video/vidconsole-uclass.c | 42 +++++++++++++++++++++++++++++++
>  include/video_console.h           |  1 +
>  3 files changed, 44 insertions(+)

See console_truetype_backspace() for how backspace works with truetype fonts.

For the normal console:

Reviewed-by: Simon Glass <sjg at chromium.org>
Tested on: sandbox
Tested-by: Simon Glass <sjg at chromium.org>

Please see nit below

>
> diff --git a/drivers/video/console_normal.c b/drivers/video/console_normal.c
> index 04f022491e5..bfd3aab8d24 100644
> --- a/drivers/video/console_normal.c
> +++ b/drivers/video/console_normal.c
> @@ -160,6 +160,7 @@ static int console_normal_probe(struct udevice *dev)
>         vc_priv->y_charsize = VIDEO_FONT_HEIGHT;
>         vc_priv->cols = vid_priv->xsize / VIDEO_FONT_WIDTH;
>         vc_priv->rows = vid_priv->ysize / VIDEO_FONT_HEIGHT;
> +       vc_priv->cursor_visible = true;
>
>         return 0;
>  }
> diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
> index f42db40d4cd..420fd86f9ac 100644
> --- a/drivers/video/vidconsole-uclass.c
> +++ b/drivers/video/vidconsole-uclass.c
> @@ -70,6 +70,26 @@ static int vidconsole_entry_start(struct udevice *dev)
>         return ops->entry_start(dev);
>  }
>
> +static void draw_cursor(struct udevice *dev, bool state)

Please add function comment

> +{
> +       struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
> +       struct video_priv *vid_priv = dev_get_uclass_priv(dev->parent);
> +       u32 tmp;
> +
> +       if (!priv->cursor_visible)
> +               return;
> +
> +       if (state) {
> +               tmp = vid_priv->colour_bg;
> +               vid_priv->colour_bg = vid_priv->colour_fg;
> +       }
> +
> +       vidconsole_putc_xy(dev, priv->xcur_frac, priv->ycur, ' ');
> +
> +       if (state)
> +               vid_priv->colour_bg = tmp;
> +}
> +
>  /* Move backwards one space */
>  static int vidconsole_back(struct udevice *dev)
>  {
> @@ -77,6 +97,8 @@ static int vidconsole_back(struct udevice *dev)
>         struct vidconsole_ops *ops = vidconsole_get_ops(dev);
>         int ret;
>
> +       draw_cursor(dev, false);
> +
>         if (ops->backspace) {
>                 ret = ops->backspace(dev);
>                 if (ret != -ENOSYS)
> @@ -103,6 +125,8 @@ static void vidconsole_newline(struct udevice *dev)
>         const int rows = CONFIG_CONSOLE_SCROLL_LINES;
>         int i, ret;
>
> +       draw_cursor(dev, false);
> +
>         priv->xcur_frac = priv->xstart_frac;
>         priv->ycur += priv->y_charsize;
>
> @@ -342,6 +366,14 @@ static void vidconsole_escape_char(struct udevice *dev, char ch)
>
>                 break;
>         }
> +       case 'l':
> +                 draw_cursor(dev, false);
> +                 priv->cursor_visible = 0;
> +                 break;
> +       case 'h':
> +                 priv->cursor_visible = 1;
> +                 draw_cursor(dev, true);
> +                 break;
>         case 'J': {
>                 int mode;
>
> @@ -516,6 +548,11 @@ int vidconsole_put_char(struct udevice *dev, char ch)
>         struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
>         int ret;
>
> +       /*
> +        * We don't need to clear the cursor since we are going to overwrite
> +        * that character anyway.
> +        */
> +
>         if (priv->escape) {
>                 vidconsole_escape_char(dev, ch);
>                 return 0;
> @@ -530,6 +567,7 @@ int vidconsole_put_char(struct udevice *dev, char ch)
>                 /* beep */
>                 break;
>         case '\r':
> +               draw_cursor(dev, false);
>                 priv->xcur_frac = priv->xstart_frac;
>                 break;
>         case '\n':
> @@ -537,6 +575,7 @@ int vidconsole_put_char(struct udevice *dev, char ch)
>                 vidconsole_entry_start(dev);
>                 break;
>         case '\t':      /* Tab (8 chars alignment) */
> +               draw_cursor(dev, false);
>                 priv->xcur_frac = ((priv->xcur_frac / priv->tab_width_frac)
>                                 + 1) * priv->tab_width_frac;
>
> @@ -554,6 +593,8 @@ int vidconsole_put_char(struct udevice *dev, char ch)
>                 break;
>         }
>
> +       draw_cursor(dev, true);
> +
>         return 0;
>  }
>
> @@ -620,6 +661,7 @@ static int vidconsole_pre_probe(struct udevice *dev)
>         struct video_priv *vid_priv = dev_get_uclass_priv(vid);
>
>         priv->xsize_frac = VID_TO_POS(vid_priv->xsize);
> +       priv->cursor_visible = false;
>
>         return 0;
>  }
> diff --git a/include/video_console.h b/include/video_console.h
> index 06b798ef10c..a908f1412e8 100644
> --- a/include/video_console.h
> +++ b/include/video_console.h
> @@ -83,6 +83,7 @@ struct vidconsole_priv {
>         int escape_len;
>         int row_saved;
>         int col_saved;
> +       bool cursor_visible;

Please add to struct comment

>         char escape_buf[32];
>  };
>
> --
> 2.17.6
>

Regards,
Simon