Create pdfless plugin files and main scripts

Also add LICENSE, README, logo and favicon

.gitignore

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+web
+build
+LICENSE

LICENSE.txt

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+MIT License
+
+Copyright (c) 2020 Shiva Prasad
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+![pdfless logo](plugin/images/logo-small.png)
+
+# pdfless
+
+*pdfless* is a customization plugin for [PDF.js][1] web viewer.
+It adds a switch for **Terminal mode** where you can change the colors and font
+of (non-scanned) PDF files. Read it as if it's on a terminal screen!
+
+## Installation
+
+1. [Download][2] the latest version (or clone this repo)
+2. `cd` into the root directory and run `./install.sh`
+3. Follow onscreen instructions
+
+## Notes
+
+Define your colors in `./plugin/colors.json` Default colors are taken from the
+[Smyck][3] colorscheme.
+
+Turning images off will improve performance and reduce overhead while switching
+between Terminal mode and normal view.
+
+*pdfless* does not attempt text-reflow (which is hopeless in PDFs). Resizing the
+text changes only the font-size without touching their position. This may result
+in disjoint / overlapping text; **this is not a bug**.
+
+## Why *pdfless*?
+
+I love reading on the terminal. The dark background, the colors, the monospaced
+font are all great for the eyes. But the stuff I have to read mostly are all in
+PDFs. PDFs are great for printing; but for reading, they suck. Bright white with
+dark text, fixed and rigid. Simply inverting the color is not a great solution;
+the font might still suck and images turn into their negative ghosts.
+
+PDF.js renders PDFs as HTML, enabling styling via CSS. *pdfless* adds a custom
+mode to the default viewer with controls to modify these styles on the go. Thus,
+it makes the PDF *less* rigid and suck *less* while reading. The name is also a
+shout-out to the Unix file-viewer utility `less`.
+
+There are PDF readers that does this in other ways (including Adobe reader), but
+I couldn't find one satisfactory. Many of them are also bloatwares (especially
+Adobe reader) and none of them goes as far as changing the font. PDF.js is small
+and runs decently in most modern browsers, requiring no additional software.
+
+[1]: https://mozilla.github.io/pdf.js/
+[2]: https://github.com/shivaprsd/pdfless/releases/latest
+[3]: https://github.com/hukl/Smyck-Color-Scheme 

install.sh

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+#!/bin/sh
+pdfjs_ver="2.6.347"
+zip="pdfjs-$pdfjs_ver-dist.zip"
+url="https://github.com/mozilla/pdf.js/releases/download/v$pdfjs_ver/$zip"
+cmd_exist() {
+    command -v "$@" >/dev/null 2>&1
+}
+
+cat <<'EOF'
+     ____  ____  ____  __    ____  ____  ____
+    (  _ \(    \(  __)(  )  (  __)/ ___)/ ___)
+     ) __/ ) D ( ) _) / (_/\ ) _) \___ \\___ \
+    (__)  (____/(__)  \____/(____)(____/(____/
+
+pdfless is a customization plugin for PDF.js web viewer.
+It adds a switch for 'Terminal mode' where you can change the colors and font
+of (non-scanned) PDF files. Read it as if it's on a terminal screen!
+
+EOF
+if ! [ -f web/viewer.html ]; then
+    echo "Downloading latest PDF.js prebuilt beta ($pdfjs_ver)..."
+    if ! [ -f "$zip" ]; then
+        if cmd_exist wget; then
+            wget -q --show-progress "$url"
+        elif cmd_exist curl; then
+            curl -fLO# "$url"
+        else
+            echo "Download failed! Manually download PDF.js and try again."
+            exit 1
+        fi
+    fi
+    printf "Extracting..."
+    unzip -q "$zip" || exit
+    echo "done."
+    rm -f "$zip"
+    rm -f web/compressed.tracemonkey-*
+fi
+
+grep -q 'pdfless.js' web/viewer.html && echo "Already installed!" && exit
+printf "Installing pdfless..."
+sed -e 's/\(<\/head>\)/<script src="..\/..\/plugin\/pdfless.js"><\/script>\1/' \
+        web/viewer.html > tmp && mv tmp web/viewer.html
+printf "done.\n\n"
+echo "Installation completed! Run \`./pdfless -h\` for usage info."
+echo "To undo this installation, run \`rm -r build web LICENSE\`."
+echo "You may move this directory anywhere, preserving its internal structure."
+echo "Optionally add it to your PATH or create a symlink to ./pdfless in PATH."

pdfless

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+#!/bin/sh
+usage() {
+    printf "Usage: pdfless [-h] <browser|url-opener> [<file>]\nArguments:\
+            \n\tbrowser|url-opener: A browser (e.g. \`firefox\`) or URL opener\
+            \n\t(e.g. \`xdg-open\`) to open the <file>.\n" 1>&2;
+}
+cmd_exist() {
+    command -v "$@" >/dev/null 2>&1
+}
+get_path() {
+    if [ -h "$1" ]; then
+        dirname "$(readlink "$1")"
+    else
+        dirname "$1"
+    fi
+}
+start_server() {
+    if cmd_exist python3; then
+        serve="python3 -m http.server $1"
+    elif cmd_exist python2; then
+        serve="python2 -m SimpleHTTPServer $1"
+    elif cmd_exist ruby; then
+        serve="ruby -run -e httpd . -p $1"
+    elif cmd_exist php; then
+        serve="php -S localhost:$1"
+    else
+        echo "pdfless: Cannot run server."
+        exit 1
+    fi
+    cd "$2" >/dev/null 2>&1 || exit
+    $serve >/dev/null 2>&1 &
+    trap "rm -rf tmp >/dev/null 2>&1; kill $!" EXIT
+    trap "exit 0" INT TERM
+    echo "pdfless: Server running at localhost:$1. ^C to quit."
+    sleep 1
+}
+
+while getopts "h" o; do
+    case "$o" in
+        h)
+            usage
+            exit 0
+            ;;
+        *)
+            usage
+            exit 1
+            ;;
+    esac
+done
+shift $((OPTIND-1))
+
+if [ -z "$1" ] || ! cmd_exist "$1"; then
+    usage
+    exit 1
+fi
+exepath="$(get_path "$0")"
+mkdir -p "$exepath/tmp" || exit
+if [ -n "$2" ]; then
+    if ! [ -f "$2" ]; then
+        echo "pdfless: No such file: $2"
+        exit 1
+    else
+        cp "$2" "$exepath/tmp/" || exit
+        fname="$(basename "$2")"
+        fpath="../tmp/$fname"
+        echo "pdfless: Opening $fname in $1..."
+    fi
+fi
+
+port=60656  # Random port in private range
+nc -z localhost $port >/dev/null 2>&1 || start_server $port "$exepath"
+$1 "http://localhost:$port/web/viewer.html?file=$fpath"
+wait

plugin/colors.json

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+{
+  "textColors": {
+    "Bright White": "#F7F7F7",
+    "White": "#B0B0B0",
+    "Gray": "#5D5D5D",
+    "Red": "#C75646",
+    "Green": "#8EB33B",
+    "Yellow": "#D0B03C",
+    "Blue": "#4E90A7",
+    "Magenta": "#C8A0D1",
+    "Cyan": "#218693",
+    "Bright Red": "#E09690",
+    "Bright Green": "#CDEE69",
+    "Bright Yellow": "#FFE377",
+    "Bright Blue": "#9CD9F0",
+    "Bright Magenta": "#FBB1F9",
+    "Bright Cyan": "#77DFD8"
+  },
+  "termColors": {
+    "background": "#242424",
+    "highlight": "rgba(33, 134, 147, 0.6)"
+  }
+}

plugin/pdfless.css

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+:root {
+  /* Fallbacks */
+  --canvasDisplay: none;
+  --termFont: none;
+  --termColor: #f7f7f7;
+  --termBG: #242424;
+  --termHL: #b0b0b0;
+  --termMode-icon: url(../plugin/images/toolbarButton-termMode.svg);
+  --fontInput-icon: url(../plugin/images/secToolbarButton-fontInput.svg);
+  --colorInput-icon: url(../plugin/images/secToolbarButton-colorInput.svg);
+  --secToolbarWidth: 220px;
+  --secToolbarBtnPad: 36px;
+  --secToolbarIconLeft: 12px;
+}
+@media (prefers-color-scheme: dark) {
+  :root {
+    --termMode-icon: url(../plugin/images/toolbarButton-termMode-dark.svg);
+  --fontInput-icon: url(../plugin/images/secToolbarButton-fontInput-dark.svg);
+  --colorInput-icon: url(../plugin/images/secToolbarButton-colorInput-dark.svg);
+  }
+}
+
+#fontInput {
+  max-width: calc(100% - 92px);
+  margin-right: 2px;
+  vertical-align: top;
+}
+#colorInput {
+  width: calc(100% + 22px);
+  height: 26px;
+}
+#colorInput:focus {
+  border-color: rgba(0, 0, 0, 0.38);
+}
+#colorSelectContainer {
+  position: relative;
+  max-width: calc(var(--secToolbarWidth) / 2 - 4px);
+}
+
+.fontControls, .colorControl {
+  position: relative;
+  padding-left: var(--secToolbarBtnPad);
+  margin-bottom: 4px;
+}
+.colorControl, .imageControl {
+  display: inline-block;
+}
+.imageControl {
+  position: relative;
+  margin-left: 6px;
+  overflow: hidden;
+}
+.imageControl label {
+  display: block
+}
+.imageControl label:hover {
+  background-color: var(--button-hover-color);
+}
+.imageControl .toolbarField[type="checkbox"]:checked + .toolbarLabel {
+  background-color: var(--toggled-btn-bg-color);
+}
+
+.fontControls::before, .colorControl::before {
+  position: absolute;
+  top: 8px;
+  left: var(--secToolbarIconLeft);
+}
+.fontControls::before {
+  content: var(--fontInput-icon);
+}
+.colorControl::before {
+  content: var(--colorInput-icon);
+  color: var(--termColor) !important;
+}
+.toolbarButton.termMode::before, .secondaryToolbarButton.termMode::before {
+  content: var(--termMode-icon);
+}

plugin/pdfless.html

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+<template id="toolbarAddon">
+  <button id="termMode" class="toolbarButton termMode hiddenLargeView" title="Toggle Terminal Mode" tabindex="30">
+    <span>Terminal Mode</span>
+  </button>
+</template>
+
+<template id="secToolbarAddon">
+  <div class="fontControls">
+    <input id="fontInput" class="toolbarField" placeholder="Terminal Font">
+    <div class="splitToolbarButton">
+      <button id="fontReduce" class="toolbarButton zoomOut" title="Reduce Fontsize">
+        <span>A-</span>
+      </button>
+      <div class="splitToolbarButtonSeparator"></div>
+      <button id="fontEnlarge" class="toolbarButton zoomIn" title="Increase Fontsize">
+        <span>A+</span>
+       </button>
+    </div>
+  </div>
+  <div class="colorControl">
+    <div id="colorSelectContainer" class="dropdownToolbarButton">
+      <select id="colorInput" class="toolbarField" title="Text Color"></select>
+    </div>
+  </div
+  ><div class="imageControl">
+    <input type="checkbox" id="imageEnable" class="toolbarField" checked
+    ><label for="imageEnable" class="toolbarLabel">Images</label>
+  </div>
+  <div class="horizontalToolbarSeparator"></div>
+  <button id="secTermMode" class="secondaryToolbarButton termMode visibleLargeView" title="Toggle Terminal Mode" tabindex="50">
+    <span>Terminal Mode</span>
+  </button>
+</template>
+
+<style id="termModeTheme">
+  .page {
+    background-color: var(--termBG) !important;
+  }
+  .textLayer {
+    opacity: 1;
+    background-color: transparent;
+  }
+  .textLayer > span, .colorControl::before {
+    color: var(--termColor) !important;
+  }
+  .canvasWrapper {
+    display: var(--canvasDisplay);
+  }
+  ::selection, .textLayer ::selection {
+    background-color: var(--termHL);
+  }
+  ::-moz-selection {
+    background-color: var(--termHL);
+  }
+</style>
+
+<style id="termModeFont">
+  .textLayer > span {
+    font-family: var(--termFont) !important;
+  }
+</style>