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Web View Module

Web View Module - webview​

Display a Web View (webview.show)​

Declaration​

webview.show {  -- All parameters are optional
  id = view_id,
  html = html_content,
  x = origin_x_coordinate,
  y = origin_y_coordinate,
  width = width,
  height = height,
  corner_radius = corner_radius,
  alpha = opacity,
  animation_duration = animation_duration,
  rotate = rotation_angle,
  level = window_level,
  opaque = opaque_range,
  ignores_hit = ignore_touch_events,
  can_drag = draggable,
}

Field Description​

  • view_id
    • integer, optional, different View IDs can be used to display multiple Web Views simultaneously. The range is 1 ~ 1000, default is 1.
  • html_content
    • string, optional, defaults to the content set during the last call to webview.show.
  • origin_x_coordinate
    • integer, optional, distance from the left side of the screen. Default is 0.
  • origin_y_coordinate
    • integer, optional, distance from the top of the screen. Default is 0.
  • width
    • integer, optional, defaults to screen width.
  • height
    • integer, optional, defaults to screen height.
  • opacity
    • float, optional, range is 0.0 ~ 1.0. Default is 1.0.
  • corner_radius
    • float, optional, default is 0.0.
  • animation_duration
    • float, optional, animation duration from the last state to the current state. Default is 0.0.
  • rotation_angle float, optional
    • Portrait: 0.0, default value.
    • Landscape with Home on the right: 90.0.
    • Upside-down portrait: 180.0.
    • Landscape with Home on the left: 270.0.
  • window_level
    • float, optional, default is 1100.0.
  • opaque_range
    • boolean, optional, default is true, meaning the background is opaque.
  • ignore_touch_events
    • boolean, optional, default is false, meaning touch events are not ignored. This property cannot be changed after the Web View is created.
  • draggable
    • boolean, optional, default is false, meaning it cannot be dragged.

Description​

Displays a WebView on the screen with the specified parameters. If the WebView is already displayed, its parameters will be updated.

The orientation of the WebView defaults to the orientation set by the last call to screen.init.

Example for this section​

Hide a Web View (webview.hide)​

Declaration​

webview.hide([ view_id ])

Parameters and Return Values​

  • View ID
    • integer, optional, default is 1.

Description​

Temporarily hides a Web View.

Example for this section​

Execute JavaScript on a Web View (webview.eval)​

Declaration​

result_text = webview.eval(js_text[, view_id])

Parameters and Return Values​

  • JS Text
    • string, JavaScript code to execute.
  • View ID
    • integer, optional, default is 1.
  • Result Text
    • string, returns the result of the executed code.

Description​

Executes a JavaScript snippet on a Web View and retrieves the result as text.

Example​

webview.eval
r = webview.eval("a = 3; b = 2; a * b;")

Get the Frame and Level Information of a Web View (webview.frame)​

Declaration​

frame_info = webview.frame([ view_id ])

Parameters and Return Values​

  • view_id
    • integer, optional, default is 1.
  • frame_info associative table

Example​

webview.frame
local frame = webview.frame()
sys.alert(
  "Position: " .. "(" .. frame.x .. "," .. frame.y .. ")\n" ..
  "Size: " .. "(w: " .. frame.width .. ", h: " .. frame.height .. ")\n" ..
  "Level: " .. "(" .. frame.level .. ")"
)

Destroy a Web View (webview.destroy)​

Declaration​

webview.destroy([ view_id ])

Parameters and Return Values​

  • view_id
    • integer, optional, default is 1.
info

When the script ends, all displayed Web Views will be automatically destroyed.

Example for this section​

Example Code​

webview.demo
require("thread")(function ()  -- Enable thread module
  local html = [==[
  <!DOCTYPE html>
  <html>
    <head>
      <script src="/js/jquery.min.js"></script>
      <script src="/js/jquery.json.min.js"></script>
      <script type="text/javascript">
        $(document).ready(function() {
          $("#toast_content").val("Toast Content");
          $("#close_page").click(function() {
            $.post("/proc_queue_push", '{"key": "Message from Web View","value": "Close Page"}', function() {});
          });
          $("#show_toast").click(function() {
            $.post("/proc_put", $.toJSON({
              key: "Toast Content",
              value: $("#toast_content").val()
            }), function() {});
            $.post("/proc_queue_push", '{"key": "Message from Web View","value": "Show Toast"}', function() {});
          });
          $("#slide_down").click(function() {
            $.post("/proc_queue_push", '{"key": "Message from Web View","value": "Slide Down"}', function() {});
            $(this).hide();
          });
          $("#full_vertical").click(function() {
            $.post("/proc_queue_push", '{"key": "Message from Web View","value": "Full Vertical"}', function() {});
          });
          $("#full_landscape").click(function() {
            $.post("/proc_queue_push", '{"key": "Message from Web View","value": "Full Landscape"}', function() {});
          });
        });
      </script>
    </head>
    <body>
      <p>Dynamic Web View Demo</p>
      <p>
        <button id="close_page" type="button">Click to Close Page</button>
      </p>
      <p>
        <button id="show_toast" type="button">Show a Toast</button>
        <input type="text" id="toast_content" />
      </p>
      <p>
        <button id="full_vertical" type="button">Full Vertical</button>
        <button id="full_landscape" type="button">Full Landscape</button>
      </p>
      <p>
        <button id="slide_down" type="button">Slide View Down</button>
      </p>
      <select>
        <option value="o1">Option 1</option>
        <option value="o2">Option 2</option>
        <option value="o3">Option 3</option>
        <option value="o4">Option 4</option>
      </select>
    </body>
  </html>
  ]==]
  --
  local w, h = screen.size()
  --
  local factor = 1  -- Default height for 2x devices
  if w == 1242 or w == 1080 then
    factor = 1.5    -- iPhone 6S Plus resolution is 3x
  elseif w == 320 or w == 768 then
    factor = 0.5    -- Pre-iPhone 3Gs resolution is 1x
  end
  --
  webview.show {    -- Reset Web View position to top-left corner
    x = 0,
    y = 0,
    width = w - 40 * factor,
    height = (500) * factor,
    alpha = 0,
    animation_duration = 0,
  }
  --
  webview.show {    -- Slide out from top-left corner in 0.3 seconds
    html = html,
    x = 20 * factor,
    y = 50 * factor,
    width = (w - 40 * factor),
    height = (500) * factor,
    corner_radius = 10,
    alpha = 0.7,
    animation_duration = 0.3,
  }
  --
  proc.queue_clear("Message from Web View", "")  -- Clear dictionary values to listen for
  local eid = thread.register_event(            -- Register event to listen for dictionary state changes
    "Message from Web View",
    function(val)
      if val == "Close Page" then
        webview.show {
          x = 20 * factor,
          y = 500 * factor * 2,
          width = (w - 40 * factor),
          height = (500 - 70) * factor,
          corner_radius = 10,
          alpha = 0,
          animation_duration = 0.8,
        }
        sys.msleep(800)
        webview.destroy()
        sys.toast("Page thread ended")
        return true                              -- Return true to stop current listener
      elseif val == "Slide Down" then
        webview.show {
          x = 20 * factor,
          y = (50 + 300) * factor,               -- Y coordinate + 300
          width = (w - 40  * factor),
          height = (500 - 70) * factor,          -- Adjust height as slide down button is hidden
          corner_radius = 10,
          alpha = 0.7,
          animation_duration = 0.5,              -- Duration 0.5 seconds
        }
      elseif val == "Full Vertical" then
        webview.show {}                          -- Set Web View to full screen
      elseif val == "Full Landscape" then
        webview.show { rotate = 90 }             -- Set Web View to full landscape
      elseif val == "Show Toast" then
        sys.toast(proc.get("Toast Content"))
      end
    end
  )
  --
  sys.msleep(3000)
  sys.toast("Main thread ended")
end)