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diff --git a/docs/image_previews/combined_with_text.md b/docs/image_previews/combined_with_text.md new file mode 100644 index 0000000..39dd8b3 --- /dev/null +++ b/docs/image_previews/combined_with_text.md @@ -0,0 +1,72 @@ +# Combining Text Preview and Thumbnails +When using a wrapper script like used for the Überzug and Überzug++ recipes, +it is possible to hand over information from the textual preview script to +the hook scripts. + +With this, it's possible to combine a textual preview and an image preview +by giving a y-offset for the image to the hook script. + +The wrapper scripts used in the Überzug and Überzug++ recipes +exports another function, +`get_preview_meta_file`, +which returns a unique, temporary file location for +each file that may be previewed in Joshuto. + +In this example, we use these file locations to store information on which y-offset +the preview image shall be drawn to be placed beneath the textual preview. + + + +## Adapt the Text Preview Script to calculate an Y-Offset + +Let's say we have this handling for JPEG and PNG files in the **`preview`** script (the “normal” preview script for textual preview): + +```bash +case "$mimetype" in + + ... + + image/png | image/jpeg) + dimension="Size `exiftool "$path" | grep '^Image Size' | awk '{print $4}'`" + tags=$(tmsu_tag_list) + echo "$dimension" + echo "$tags" + meta_file="$(get_preview_meta_file $path)" + let y_offset=`printf "${tags}" | sed -n '=' | wc -l`+2 + echo "y-offset $y_offset" > "$meta_file" + exit 4 + ;; +``` + +Here, we fetch some data we want as text (dimensions of the image and some tags) and just print it out for +Joshuto to show like for just a textual preview. +Additionally, we calculate the height of our output and write it to a temporary file, specific for the +current `$path`, which has been provided by the wrapper script via the `get_preview_meta_file` function. + +## Adapt the "preview-shown" Script to put the Image at the right Y-Offset + +After we have the y-offset available, we adapt the “preview shown” hook script as follows: + +```bash +... + +case "$mimetype" in + image/png | image/jpeg) + meta_file="$(get_preview_meta_file $path)" + y_offset=`cat "$meta_file" | grep "y-offset" | awk '{print $2}'` + y=$(( $y + $y_offset )) + show_image "$path" $x $y $width $height + ;; + *) + remove_image + +esac +``` + +Here, we again get the path of our temporary file and then +use that offset information to +display the image preview just below the textual output. + +Joshuto will have cached the textual output but all the temporary files will remain until +Joshuto (and the wrapper script) are exited, so they will remain available for the hook scripts. + |