画像の上に長方形を描くR光沢

この質問に対する受け入れられた回答について詳しく説明したいます。

以下の最小限の光沢のあるアプリ（承認された回答から抽出）を次の機能で改善することを検討しています。

• 1）長方形とテキストラベルを描画します。ラベルはR（input$foo）、たとえばドロップダウンから取得されます。ラベルが画像の外側にあるエッジケースを回避するには、ラベルを長方形の内側に配置する必要があります。
• 2）別の色を使用するラベルに応じて、長方形とそのラベルにを
• 3）ユーザーが長方形内をダブルクリックして削除する機能。複数の一致（オーバーラップ、ネスト）の場合、最小面積の長方形を削除する必要があります。

1）のブラウニーポイント：ドロップダウンは、次のようにカーソルの横に表示されます（ここにコードを記述）。可能であれば、ドロップダウンリストはserver.Rから渡す必要があり、固定/ハードコーディングしないでください。その理由は、ユーザー入力によっては、別のドロップダウンが表示される可能性があるためです。たとえば、果物用c('banana','pineapple','grapefruit')に1つのドロップダウン、動物用に1つのドロップダウンc('raccoon','dog','cat')などがあります。

# JS and CSS modified from: https://stackoverflow.com/a/17409472/8099834
css <- "
    #canvas {
        width:2000px;
        height:2000px;
        border: 10px solid transparent;
    }
    .rectangle {
        border: 5px solid #FFFF00;
        position: absolute;
    }
"

js <- 
"function initDraw(canvas) {
    var mouse = {
        x: 0,
        y: 0,
        startX: 0,
        startY: 0
    };
    function setMousePosition(e) {
        var ev = e || window.event; //Moz || IE
        if (ev.pageX) { //Moz
            mouse.x = ev.pageX + window.pageXOffset;
            mouse.y = ev.pageY + window.pageYOffset;
        } else if (ev.clientX) { //IE
            mouse.x = ev.clientX + document.body.scrollLeft;
            mouse.y = ev.clientY + document.body.scrollTop;
        }
    };

    var element = null;    
    canvas.onmousemove = function (e) {
        setMousePosition(e);
        if (element !== null) {
            element.style.width = Math.abs(mouse.x - mouse.startX) + 'px';
            element.style.height = Math.abs(mouse.y - mouse.startY) + 'px';
            element.style.left = (mouse.x - mouse.startX < 0) ? mouse.x + 'px' : mouse.startX + 'px';
            element.style.top = (mouse.y - mouse.startY < 0) ? mouse.y + 'px' : mouse.startY + 'px';
        }
    }

    canvas.onclick = function (e) {
        if (element !== null) {
           var coord = {
               left: element.style.left,
               top: element.style.top,
               width: element.style.width,
               height: element.style.height
            };
            Shiny.onInputChange('rectCoord', coord);
            element = null;
            canvas.style.cursor = \"default\";
        } else {
            mouse.startX = mouse.x;
            mouse.startY = mouse.y;
            element = document.createElement('div');
            element.className = 'rectangle'
            element.style.left = mouse.x + 'px';
            element.style.top = mouse.y + 'px';
            canvas.appendChild(element);
            canvas.style.cursor = \"crosshair\";
        }
    }
};
$(document).on('shiny:sessioninitialized', function(event) {
    initDraw(document.getElementById('canvas'));
});
"

library(shiny)

ui <- fluidPage(
  tags$head(
      tags$style(css),
      tags$script(HTML(js))
  ),
  fluidRow(
      column(width = 6, 
             # inline is necessary
             # ...otherwise we can draw rectangles over entire fluidRow
             uiOutput("canvas", inline = TRUE)),
      column(
          width = 6,
          verbatimTextOutput("rectCoordOutput")
          )
  )
)

server <- function(input, output, session) {
    output$canvas <- renderUI({
        tags$img(src = "https://www.r-project.org/logo/Rlogo.png")
    })
    output$rectCoordOutput <- renderPrint({
        input$rectCoord
    })

}

shinyApp(ui, server)

このソリューションはkyamaguのbbox_annotatorを使用し、demo.htmlに基づいています。私はJSに慣れていないので、かわいくはありません。制限は次のとおりです。

1. 別の画像URLを選択すると、以前の長方形が削除されます
2. 私はJSを少し編集して長方形/テキストの色を変更したので、元のリポジトリから直接プルすることはできません
3. 私の変更はおそらくinput_method = "fixed"と "text"を壊しました、私はinput_method = "select"のみをテストしました

ui.R

# Adapted from https://github.com/kyamagu/bbox-annotator/
# Edited original JS to add color_list as an option
# ...should be the same length as labels
# ...and controls the color of the rectangle
# ...will probably be broken for input_method = "fixed" or "text"
# Also added color as a value in each rectangle entry
js <- '
    $(document).ready(function() {
       // define options to pass to bounding box constructor
        var options = {
          url: "https://www.r-project.org/logo/Rlogo.svg",
          input_method: "select", 
          labels: [""],
          color_list:  [""], 
          onchange: function(entries) {
                Shiny.onInputChange("rectCoord", JSON.stringify(entries, null, "  "));
          }
        };

        // Initialize the bounding-box annotator.
        var annotator = new BBoxAnnotator(options);

        // Initialize the reset button.
        $("#reset_button").click(function(e) {
            annotator.clear_all();
        })

        // define function to reset the bbox
        // ...upon choosing new label category or new url
        function reset_bbox(options) {
          document.getElementById("bbox_annotator").setAttribute("style", "display:inline-block");
          $(".image_frame").remove();
          annotator = new BBoxAnnotator(options);
        }

        // update image url from shiny
        Shiny.addCustomMessageHandler("change-img-url", function(url) {
          options.url = url;
          options.width = null;
          options.height = null;
          reset_bbox(options);
        });

        // update colors and categories from shiny
        Shiny.addCustomMessageHandler("update-category-list", function(vals) {
          options.labels = Object.values(vals);
          options.color_list = Object.keys(vals);
          reset_bbox(options);
        });

        // redraw rectangles based on list of entries
        Shiny.addCustomMessageHandler("redraw-rects", function(vals) {
          var arr = JSON.parse(vals);
          arr.forEach(function(rect){
             annotator.add_entry(rect);
          });
          if (annotator.onchange) {
             annotator.onchange(annotator.entries);
          }
        }); 
    });
'

ui <- fluidPage(
    tags$head(tags$script(HTML(js)),
              tags$head(
                  tags$script(src = "bbox_annotation.js")
              )),
    titlePanel("Bounding box annotator demo"),
    sidebarLayout(
        sidebarPanel(
            selectInput(
                "img_url",
                "URLs",
                c(
                    "https://www.r-project.org/logo/Rlogo.svg",
                    "https://github.githubassets.com/images/modules/logos_page/GitHub-Mark.png"
                )
            ),
            selectInput("category_type", "Label Category", c("animals", "fruits")),
            div(HTML(
                '<input id="reset_button" type="reset" />'
            )),
            HTML(
                '<input id="annotation_data" name="annotation_data" type="hidden" />'
            ),
            hr(),
            h4("Entries"),
            verbatimTextOutput("rectCoordOutput")
        ),
        mainPanel(div(id = "bbox_annotator", style = "display:inline-block"))
    )
)

server.R

server <- function(input, output, session) {
    # user choices
    output$rectCoordOutput <- renderPrint({
        if(!is.null(input$rectCoord)) {
            as.data.frame(jsonlite::fromJSON(input$rectCoord))
        }
    })
    # send chosen URL from shiny to JS
    observeEvent(input$img_url, {
        session$sendCustomMessage("change-img-url", input$img_url)
    })
    # send chosen category list from shiny to JS
    observeEvent(input$category_type, {
        vals <- switch(input$category_type, 
               fruits = list("yellow" = "banana", 
                          "orange" = "pineapple",
                          "pink" = "grapefruit"),
               animals = list("grey" = "raccoon",
                           "brown" = "dog",
                           "tan" = "cat")
               )
        # update category list
        session$sendCustomMessage("update-category-list", vals)
        # redraw rectangles
        session$sendCustomMessage("redraw-rects", input$rectCoord)
    })
}

www / bbox_annotation.js

// Generated by CoffeeScript 2.5.0
(function() {
  // https://github.com/kyamagu/bbox-annotator/blob/master/bbox_annotator.coffee
  // Use coffee-script compiler to obtain a javascript file.

  //    coffee -c bbox_annotator.coffee

  // See http://coffeescript.org/

  // BBox selection window.
  var BBoxSelector;

  BBoxSelector = class BBoxSelector {
    // Initializes selector in the image frame.
    constructor(image_frame, options) {
      if (options == null) {
        options = {};
      }
      options.input_method || (options.input_method = "text");
      this.image_frame = image_frame;
      this.border_width = options.border_width || 2;
      this.selector = $('<div class="bbox_selector"></div>');
      this.selector.css({
        // rectangle color when dragging
        "border": this.border_width + "px dotted rgb(127,255,127)",
        "position": "absolute"
      });
      this.image_frame.append(this.selector);
      this.selector.css({
        "border-width": this.border_width
      });
      this.selector.hide();
      this.create_label_box(options);
    }

    // Initializes a label input box.
    create_label_box(options) {
      var i, label, len, ref;
      options.labels || (options.labels = ["object"]);
      this.label_box = $('<div class="label_box" style="z-index: 1000"></div>');
      this.label_box.css({
        "position": "absolute"
      });
      this.image_frame.append(this.label_box);
      switch (options.input_method) {
        case 'select':
          if (typeof options.labels === "string") {
            options.labels = [options.labels];
          }
          this.label_input = $('<select class="label_input" name="label"></select>');
          this.label_box.append(this.label_input);
          this.label_input.append($('<option value>choose an item</option>'));
          ref = options.labels;
          for (i = 0, len = ref.length; i < len; i++) {
            label = ref[i];
            this.label_input.append('<option value="' + label + '">' + label + '</option>');
          }
          this.label_input.change(function(e) {
            return this.blur();
          });
          break;
        case 'text':
          if (typeof options.labels === "string") {
            options.labels = [options.labels];
          }
          this.label_input = $('<input class="label_input" name="label" ' + 'type="text" value>');
          this.label_box.append(this.label_input);
          this.label_input.autocomplete({
            source: options.labels || [''],
            autoFocus: true
          });
          break;
        case 'fixed':
          if ($.isArray(options.labels)) {
            options.labels = options.labels[0];
          }
          this.label_input = $('<input class="label_input" name="label" type="text">');
          this.label_box.append(this.label_input);
          this.label_input.val(options.labels);
          break;
        default:
          throw 'Invalid label_input parameter: ' + options.input_method;
      }
      return this.label_box.hide();
    }

    // Crop x and y to the image size.
    crop(pageX, pageY) {
      var point;
      return point = {
        x: Math.min(Math.max(Math.round(pageX - this.image_frame.offset().left), 0), Math.round(this.image_frame.width() - 1)),
        y: Math.min(Math.max(Math.round(pageY - this.image_frame.offset().top), 0), Math.round(this.image_frame.height() - 1))
      };
    }

    // When a new selection is made.
    start(pageX, pageY) {
      this.pointer = this.crop(pageX, pageY);
      this.offset = this.pointer;
      this.refresh();
      this.selector.show();
      $('body').css('cursor', 'crosshair');
      return document.onselectstart = function() {
        return false;
      };
    }

    // When a selection updates.
    update_rectangle(pageX, pageY) {
      this.pointer = this.crop(pageX, pageY);
      return this.refresh();
    }

    // When starting to input label.
    input_label(options) {
      $('body').css('cursor', 'default');
      document.onselectstart = function() {
        return true;
      };
      this.label_box.show();
      return this.label_input.focus();
    }

    // Finish and return the annotation.
    finish(options) {
      var data;
      this.label_box.hide();
      this.selector.hide();
      data = this.rectangle();
      data.label = $.trim(this.label_input.val().toLowerCase());
      if (options.input_method !== 'fixed') {
        this.label_input.val('');
      }
      return data;
    }

    // Get a rectangle.
    rectangle() {
      var rect, x1, x2, y1, y2;
      x1 = Math.min(this.offset.x, this.pointer.x);
      y1 = Math.min(this.offset.y, this.pointer.y);
      x2 = Math.max(this.offset.x, this.pointer.x);
      y2 = Math.max(this.offset.y, this.pointer.y);
      return rect = {
        left: x1,
        top: y1,
        width: x2 - x1 + 1,
        height: y2 - y1 + 1
      };
    }

    // Update css of the box.
    refresh() {
      var rect;
      rect = this.rectangle();
      this.selector.css({
        left: (rect.left - this.border_width) + 'px',
        top: (rect.top - this.border_width) + 'px',
        width: rect.width + 'px',
        height: rect.height + 'px'
      });
      return this.label_box.css({
        left: (rect.left - this.border_width) + 'px',
        top: (rect.top + rect.height + this.border_width) + 'px'
      });
    }

    // Return input element.
    get_input_element() {
      return this.label_input;
    }

  };

  // Annotator object definition.
  this.BBoxAnnotator = class BBoxAnnotator {
    // Initialize the annotator layout and events.
    constructor(options) {
      var annotator, image_element;
      annotator = this;
      this.annotator_element = $(options.id || "#bbox_annotator");
      // allow us to access colors and labels in future steps
      this.color_list = options.color_list;
      this.label_list = options.labels;
      this.border_width = options.border_width || 2;
      this.show_label = options.show_label || (options.input_method !== "fixed");
      if (options.multiple != null) {
        this.multiple = options.multiple;
      } else {
        this.multiple = true;
      }
      this.image_frame = $('<div class="image_frame"></div>');
      this.annotator_element.append(this.image_frame);
      if (options.guide) {
        annotator.initialize_guide(options.guide);
      }
      image_element = new Image();
      image_element.src = options.url;
      image_element.onload = function() {
        options.width || (options.width = image_element.width);
        options.height || (options.height = image_element.height);
        annotator.annotator_element.css({
          "width": (options.width + annotator.border_width) + 'px',
          "height": (options.height + annotator.border_width) + 'px',
          "padding-left": (annotator.border_width / 2) + 'px',
          "padding-top": (annotator.border_width / 2) + 'px',
          "cursor": "crosshair",
          "overflow": "hidden"
        });
        annotator.image_frame.css({
          "background-image": "url('" + image_element.src + "')",
          "width": options.width + "px",
          "height": options.height + "px",
          "position": "relative"
        });
        annotator.selector = new BBoxSelector(annotator.image_frame, options);
        return annotator.initialize_events(options);
      };
      image_element.onerror = function() {
        return annotator.annotator_element.text("Invalid image URL: " + options.url);
      };
      this.entries = [];
      this.onchange = options.onchange;
    }

    // Initialize events.
    initialize_events(options) {
      var annotator, selector, status;
      status = 'free';
      this.hit_menuitem = false;
      annotator = this;
      selector = annotator.selector;
      this.annotator_element.mousedown(function(e) {
        if (!annotator.hit_menuitem) {
          switch (status) {
            case 'free':
            case 'input':
              if (status === 'input') {
                selector.get_input_element().blur();
              }
              if (e.which === 1) { // left button
                selector.start(e.pageX, e.pageY);
                status = 'hold';
              }
          }
        }
        annotator.hit_menuitem = false;
        return true;
      });
      $(window).mousemove(function(e) {
        var offset;
        switch (status) {
          case 'hold':
            selector.update_rectangle(e.pageX, e.pageY);
        }
        if (annotator.guide_h) {
          offset = annotator.image_frame.offset();
          annotator.guide_h.css('top', Math.floor(e.pageY - offset.top) + 'px');
          annotator.guide_v.css('left', Math.floor(e.pageX - offset.left) + 'px');
        }
        return true;
      });
      $(window).mouseup(function(e) {
        switch (status) {
          case 'hold':
            selector.update_rectangle(e.pageX, e.pageY);
            selector.input_label(options);
            status = 'input';
            if (options.input_method === 'fixed') {
              selector.get_input_element().blur();
            }
        }
        return true;
      });
      selector.get_input_element().blur(function(e) {
        var data;
        switch (status) {
          case 'input':
            data = selector.finish(options);
            if (data.label) {
              // store color with the entry
              // ...so we can redraw the rectangle upon changing label category
              data.color = annotator.color_list[annotator.label_list.indexOf(data.label)];
              annotator.add_entry(data);
              if (annotator.onchange) {
                annotator.onchange(annotator.entries);
              }
            }
            status = 'free';
        }
        return true;
      });
      selector.get_input_element().keypress(function(e) {
        switch (status) {
          case 'input':
            if (e.which === 13) {
              selector.get_input_element().blur();
            }
        }
        return e.which !== 13;
      });
      selector.get_input_element().mousedown(function(e) {
        return annotator.hit_menuitem = true;
      });
      selector.get_input_element().mousemove(function(e) {
        return annotator.hit_menuitem = true;
      });
      selector.get_input_element().mouseup(function(e) {
        return annotator.hit_menuitem = true;
      });
      return selector.get_input_element().parent().mousedown(function(e) {
        return annotator.hit_menuitem = true;
      });
    }

    // Add a new entry.
    add_entry(entry) {
      var annotator, box_element, close_button, text_box;
      if (!this.multiple) {
        this.annotator_element.find(".annotated_bounding_box").detach();
        this.entries.splice(0);
      }
      this.entries.push(entry);
      box_element = $('<div class="annotated_bounding_box"></div>');
      box_element.appendTo(this.image_frame).css({
        // rectangle color -- when stopped dragging
        "border": this.border_width + "px solid " + entry.color,
        "position": "absolute",
        "top": (entry.top - this.border_width) + "px",
        "left": (entry.left - this.border_width) + "px",
        "width": entry.width + "px",
        "height": entry.height + "px",
        // text color when stopped dragging
        "color": entry.color,
        "font-family": "monospace",
        "font-size": "small"
      });
      close_button = $('<div></div>').appendTo(box_element).css({
        "position": "absolute",
        "top": "-8px",
        "right": "-8px",
        "width": "16px",
        "height": "0",
        "padding": "16px 0 0 0",
        "overflow": "hidden",
        "color": "#fff",
        "background-color": "#030",
        "border": "2px solid #fff",
        "-moz-border-radius": "18px",
        "-webkit-border-radius": "18px",
        "border-radius": "18px",
        "cursor": "pointer",
        "-moz-user-select": "none",
        "-webkit-user-select": "none",
        "user-select": "none",
        "text-align": "center"
      });
      $("<div></div>").appendTo(close_button).html('&#215;').css({
        "display": "block",
        "text-align": "center",
        "width": "16px",
        "position": "absolute",
        "top": "-2px",
        "left": "0",
        "font-size": "16px",
        "line-height": "16px",
        "font-family": '"Helvetica Neue", Consolas, Verdana, Tahoma, Calibri, ' + 'Helvetica, Menlo, "Droid Sans", sans-serif'
      });
      text_box = $('<div></div>').appendTo(box_element).css({
        "overflow": "hidden"
      });
      if (this.show_label) {
        text_box.text(entry.label);
      }
      annotator = this;
      box_element.hover((function(e) {
        return close_button.show();
      }), (function(e) {
        return close_button.hide();
      }));
      close_button.mousedown(function(e) {
        return annotator.hit_menuitem = true;
      });
      close_button.click(function(e) {
        var clicked_box, index;
        clicked_box = close_button.parent(".annotated_bounding_box");
        index = clicked_box.prevAll(".annotated_bounding_box").length;
        clicked_box.detach();
        annotator.entries.splice(index, 1);
        return annotator.onchange(annotator.entries);
      });
      return close_button.hide();
    }

    // Clear all entries.
    clear_all(e) {
      this.annotator_element.find(".annotated_bounding_box").detach();
      this.entries.splice(0);
      return this.onchange(this.entries);
    }

    // Add crosshair guide.
    initialize_guide(options) {
      this.guide_h = $('<div class="guide_h"></div>').appendTo(this.image_frame).css({
        "border": "1px dotted " + (options.color || '#000'),
        "height": "0",
        "width": "100%",
        "position": "absolute",
        "top": "0",
        "left": "0"
      });
      return this.guide_v = $('<div class="guide_v"></div>').appendTo(this.image_frame).css({
        "border": "1px dotted " + (options.color || '#000'),
        "height": "100%",
        "width": "0",
        "position": "absolute",
        "top": "0",
        "left": "0"
      });
    }

  };

}).call(this);