X-Git-Url: https://git-public.kairo.at/?p=mandelbrot.git;a=blobdiff_plain;f=xulapp%2Fchrome%2Fmandelbrot%2Fcontent%2Fmandelbrot.js;h=788e198bd6059fba5259f21dce6bb6ab2b8b1a06;hp=d887b82e71f0d9dcd620d449d34ff28fdad48f31;hb=305865993932a42afc891deb5acc046b62949c9e;hpb=9c2ca9fa0da990b69c278ae100ccd8dfb631f4eb

diff --git a/xulapp/chrome/mandelbrot/content/mandelbrot.js b/xulapp/chrome/mandelbrot/content/mandelbrot.js
index d887b82..788e198 100644
--- a/xulapp/chrome/mandelbrot/content/mandelbrot.js
+++ b/xulapp/chrome/mandelbrot/content/mandelbrot.js
@@ -40,12 +40,64 @@ var gPref = Components.classes["@mozilla.org/preferences-service;1"]
                       .getService(Components.interfaces.nsIPrefService)
                       .getBranch(null);
 var gStartTime = 0;
+var gMbrotBundle;
+var gCurrentImageData;
 
 function Startup() {
   updateIterMenu();
   updatePaletteMenu();
-  document.getElementById("statusLabel").value =
-      document.getElementById("mbrotBundle").getString("statusEmpty");
+  gMbrotBundle = document.getElementById("mbrotBundle");
+  document.getElementById("statusLabel").value = gMbrotBundle.getString("statusEmpty");
+}
+
+function adjustCoordsAndDraw(aC_min, aC_max) {
+  let iWidth = 0;
+  try {
+    iWidth = gPref.getIntPref("mandelbrot.image.width");
+  }
+  catch (e) { }
+  if ((iWidth < 10) || (iWidth > 5000)) {
+    iWidth = 300;
+    gPref.setIntPref("mandelbrot.image.width", iWidth);
+  }
+  let iHeight = 0;
+  try {
+    iHeight = gPref.getIntPref("mandelbrot.image.height");
+  }
+  catch (e) { }
+  if ((iHeight < 10) || (iHeight > 5000)) {
+    iHeight = 300;
+    gPref.setIntPref("mandelbrot.image.height", iHeight);
+  }
+
+  // correct coordinates
+  if (aC_min.r < -2)
+    aC_min.r = -2;
+  if (aC_max.r > 2)
+    aC_max.r = 2;
+  if ((aC_min.r > 2) || (aC_max.r < -2) || (aC_min.r >= aC_max.r)) {
+    aC_min.r = -2.0; aC_max.r = 1.0;
+  }
+  if (aC_min.i < -2)
+    aC_min.i = -2;
+  if (aC_max.i > 2)
+    aC_max.i = 2;
+  if ((aC_min.i > 2) || (aC_max.i < -2) || (aC_min.i >= aC_max.i)) {
+    aC_min.i = -1.3; aC_max.i = 1.3;
+  }
+
+  let CWidth = aC_max.r - aC_min.r;
+  let CHeight = aC_max.i - aC_min.i;
+  let C_mid = new complex(aC_min.r + CWidth / 2, aC_min.i + CHeight / 2);
+
+  let CRatio = Math.max(CWidth / iWidth, CHeight / iHeight);
+
+  gPref.setCharPref("mandelbrot.last_image.Cr_min", C_mid.r - iWidth * CRatio / 2);
+  gPref.setCharPref("mandelbrot.last_image.Cr_max", C_mid.r + iWidth * CRatio / 2);
+  gPref.setCharPref("mandelbrot.last_image.Ci_min", C_mid.i - iHeight * CRatio / 2);
+  gPref.setCharPref("mandelbrot.last_image.Ci_max", C_mid.i + iHeight * CRatio / 2);
+
+  drawImage();
 }
 
 function drawImage() {
@@ -54,8 +106,7 @@ function drawImage() {
 
   document.getElementById("drawButton").hidden = true;
 
-  document.getElementById("statusLabel").value =
-      document.getElementById("mbrotBundle").getString("statusDrawing");
+  document.getElementById("statusLabel").value = gMbrotBundle.getString("statusDrawing");
 
   let Cr_min = -2.0;
   let Cr_max = 1.0;
@@ -64,8 +115,8 @@ function drawImage() {
     Cr_max = parseFloat(gPref.getCharPref("mandelbrot.last_image.Cr_max"));
   }
   catch (e) { }
-  if ((Cr_min < -2) || (Cr_min > 2) ||
-      (Cr_max < -2) || (Cr_max > 2) || (Cr_min >= Cr_max)) {
+  if ((Cr_min < -3) || (Cr_min > 2) ||
+      (Cr_max < -3) || (Cr_max > 2) || (Cr_min >= Cr_max)) {
     Cr_min = -2.0; Cr_max = 1.0;
   }
   gPref.setCharPref("mandelbrot.last_image.Cr_min", Cr_min);
@@ -78,9 +129,9 @@ function drawImage() {
     Ci_max = parseFloat(gPref.getCharPref("mandelbrot.last_image.Ci_max"));
   }
   catch (e) { }
-  if ((Ci_min < -2) || (Ci_min > 2) ||
-      (Ci_max < -2) || (Ci_max > 2) || (Ci_min >= Ci_max)) {
-    Ci_min = -2.0; Ci_max = 1.0;
+  if ((Ci_min < -2.5) || (Ci_min > 2.5) ||
+      (Ci_max < -2.5) || (Ci_max > 2.5) || (Ci_min >= Ci_max)) {
+    Ci_min = -1.5; Ci_max = 1.5;
   }
   gPref.setCharPref("mandelbrot.last_image.Ci_min", Ci_min);
   gPref.setCharPref("mandelbrot.last_image.Ci_max", Ci_max);
@@ -107,6 +158,14 @@ function drawImage() {
     gPref.setIntPref("mandelbrot.image.height", iHeight);
   }
 
+  gCurrentImageData = {
+    C_min: new complex(Cr_min, Ci_min),
+    C_max: new complex(Cr_max, Ci_max),
+    iWidth: iWidth,
+    iHeight: iHeight,
+    iterMax: iterMax
+  };
+
   canvas.width = iWidth;
   canvas.height = iHeight;
 
@@ -120,34 +179,34 @@ function drawImage() {
 }
 
 function drawLine(line, dimensions, canvas, context, iterMax, algorithm) {
-    let Cr_min = dimensions[0];
-    let Cr_max = dimensions[1];
-    let Cr_scale = Cr_max - Cr_min;
-
-    let Ci_min = dimensions[2];
-    let Ci_max = dimensions[3];
-    let Ci_scale = Ci_max - Ci_min;
-
-    let pixels = [];
-    for (var img_y = line; img_y < canvas.height && img_y < line+8; img_y++)
-      for (let img_x = 0; img_x < canvas.width; img_x++) {
-        let C = new complex(Cr_min + (img_x / canvas.width) * Cr_scale,
-                            Ci_min + (img_y / canvas.height) * Ci_scale);
-        pixels.push.apply(pixels, drawPoint(context, img_x, img_y, C, iterMax, algorithm));
-      }
-    context.putImageData({width: canvas.width, height: pixels.length/4/canvas.width, data: pixels}, 0, line);
+  let Cr_min = dimensions[0];
+  let Cr_max = dimensions[1];
+  let Cr_scale = Cr_max - Cr_min;
+
+  let Ci_min = dimensions[2];
+  let Ci_max = dimensions[3];
+  let Ci_scale = Ci_max - Ci_min;
+
+  let pixels = [];
+  for (var img_y = line; img_y < canvas.height && img_y < line+8; img_y++)
+    for (let img_x = 0; img_x < canvas.width; img_x++) {
+      let C = new complex(Cr_min + (img_x / canvas.width) * Cr_scale,
+                          Ci_min + (img_y / canvas.height) * Ci_scale);
+      pixels.push.apply(pixels, drawPoint(context, img_x, img_y, C, iterMax, algorithm));
+    }
+  context.putImageData({width: canvas.width, height: pixels.length/4/canvas.width, data: pixels}, 0, line);
 
-    if (img_y < canvas.height)
-      setTimeout(drawLine, 0, img_y, dimensions, canvas, context, iterMax, algorithm);
-    else if (gStartTime)
-      EndCalc();
+  if (img_y < canvas.height)
+    setTimeout(drawLine, 0, img_y, dimensions, canvas, context, iterMax, algorithm);
+  else if (gStartTime)
+    EndCalc();
 }
 
 function EndCalc() {
   let endTime = new Date();
   let timeUsed = (endTime.getTime() - gStartTime.getTime()) / 1000;
   document.getElementById("statusLabel").value =
-      document.getElementById("mbrotBundle").getFormattedString("statusTime", [timeUsed.toFixed(3)]);
+      gMbrotBundle.getFormattedString("statusTime", [timeUsed.toFixed(3)]);
   gStartTime = 0;
 }
 
@@ -258,10 +317,62 @@ function getColorPalette(palName) {
       }
       palette[1024] = [0, 0, 0, 255];
       break;
+    case 'rainbow-squared1':
+      for (let i = 0; i < 34; i++) {
+        let cc = Math.floor(i * 255 / 33);
+        palette[i] = [cc, 0, 0, 255];
+      }
+      for (let i = 0; i < 137; i++) {
+        let cc = Math.floor(i * 255 / 136);
+        palette[34 + i] = [255, cc, 0, 255];
+      }
+      for (let i = 0; i < 307; i++) {
+        let cc = Math.floor(i * 255 / 306);
+        palette[171 + i] = [255 - cc, 255, cc, 255];
+      }
+      for (let i = 0; i < 546; i++) {
+        let cc = Math.floor(i * 255 / 545);
+        palette[478 + i] = [cc, 255 - cc, 255, 255];
+      }
+      palette[1024] = [0, 0, 0, 255];
+      break;
+    case 'rainbow-linear2':
+      for (let i = 0; i < 205; i++) {
+        let cc = Math.floor(i * 255 / 204);
+        palette[i] = [255, cc, 0, 255];
+        palette[204 + i] = [255 - cc, 255, 0, 255];
+        palette[409 + i] = [0, 255, cc, 255];
+        palette[614 + i] = [0, 255 - cc, 255, 255];
+        palette[819 + i] = [cc, 0, 255, 255];
+      }
+      palette[1024] = [0, 0, 0, 255];
+      break;
+    case 'rainbow-squared2':
+      for (let i = 0; i < 19; i++) {
+        let cc = Math.floor(i * 255 / 18);
+        palette[i] = [255, cc, 0, 255];
+      }
+      for (let i = 0; i < 74; i++) {
+        let cc = Math.floor(i * 255 / 73);
+        palette[19 + i] = [255 - cc, 255, 0, 255];
+      }
+      for (let i = 0; i < 168; i++) {
+        let cc = Math.floor(i * 255 / 167);
+        palette[93 + i] = [0, 255, cc, 255];
+      }
+      for (let i = 0; i < 298; i++) {
+        let cc = Math.floor(i * 255 / 297);
+        palette[261 + i] = [0, 255 - cc, 255, 255];
+      }
+      for (let i = 0; i < 465; i++) {
+        let cc = Math.floor(i * 255 / 464);
+        palette[559 + i] = [cc, 0, 255, 255];
+      }
+      palette[1024] = [0, 0, 0, 255];
+      break;
   }
-/*
-Select Case palnr
-Case 1  'Standard-Palette (QB-Colors)
+  /*
+     'Standard-Palette (QB-Colors)
      For i = 0 To 1024
          xx = CInt(i * 500 / 1024 + 2)
          If xx <= 15 Then clr = xx
@@ -269,54 +380,7 @@ Case 1  'Standard-Palette (QB-Colors)
          If xx >= 500 Then clr = 0
          palette(i) = QBColor(clr)
      Next
-Case 3  'Regenbogen-Palette 1 (qu.)
-     For i = 0 To 33
-         clr = CInt(i * 255 / 33)
-         palette(i) = RGB(clr, 0, 0)
-     Next
-     For i = 0 To 136
-         clr = CInt(i * 255 / 136)
-         palette(34 + i) = RGB(255, clr, 0)
-     Next
-     For i = 0 To 306
-         clr = CInt(i * 255 / 306)
-         palette(171 + i) = RGB(255 - clr, 255, clr)
-     Next
-     For i = 0 To 545
-         clr = CInt(i * 255 / 545)
-         palette(478 + i) = RGB(clr, 255 - clr, 255)
-     Next
-Case 4  'Regenbogen-Palette 2 (linear)
-     For i = 0 To 204
-         clr = CInt(i * 255 / 204)
-         palette(i) = RGB(255, clr, 0)
-         palette(204 + i) = RGB(255 - clr, 255, 0)
-         palette(409 + i) = RGB(0, 255, clr)
-         palette(614 + i) = RGB(0, 255 - clr, 255)
-         palette(819 + i) = RGB(clr, 0, 255)
-     Next
-Case 5  'Regenbogen-Palette 2 (qu.)
-     For i = 0 To 18
-         clr = CInt(i * 255 / 18)
-         palette(i) = RGB(255, clr, 0)
-     Next
-     For i = 0 To 73
-         clr = CInt(i * 255 / 73)
-         palette(20 + i) = RGB(255 - clr, 255, 0)
-     Next
-     For i = 0 To 167
-         clr = CInt(i * 255 / 167)
-         palette(93 + i) = RGB(0, 255, clr)
-     Next
-     For i = 0 To 297
-         clr = CInt(i * 255 / 297)
-         palette(261 + i) = RGB(0, 255 - clr, 255)
-     Next
-     For i = 0 To 464
-         clr = CInt(i * 255 / 464)
-         palette(559 + i) = RGB(clr, 0, 255)
-     Next
-*/
+  */
   return palette;
 }
 
@@ -348,14 +412,39 @@ function mouseevent(etype, event) {
                      y: event.clientY - canvas.offsetTop};
       break;
     case 'up':
-      if (event.button == 0) {
-        var prompts = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
+      if (event.button == 0 && zoomstart) {
+        let zoomend = {x: event.clientX - canvas.offsetLeft,
+                       y: event.clientY - canvas.offsetTop};
+
+        // make sure zoomend is bigger than zoomstart
+        if ((zoomend.x == zoomstart.x) || (zoomend.y == zoomstart.y)) {
+          // cannot zoom what has no area, discard it
+          zoomstart = undefined;
+          return;
+        }
+        if (zoomend.x < zoomstart.x)
+          [zoomend.x, zoomstart.x] = [zoomstart.x, zoomend.x];
+        if (zoomend.y < zoomstart.y)
+          [zoomend.y, zoomstart.y] = [zoomstart.y, zoomend.y];
+
+        let prompts = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
                                 .getService(Components.interfaces.nsIPromptService);
-        var ok = prompts.confirm(null, "XXX Zoom in",
-            zoomstart.x + ',' + zoomstart.y + '-' +
-            (event.clientX - canvas.offsetLeft) + ',' +
-            (event.clientY - canvas.offsetTop));
+        let ok = prompts.confirm(null, gMbrotBundle.getString("zoomConfirmTitle"),
+                                 gMbrotBundle.getString("zoomConfirmLabel"));
         // ok is now true if OK was clicked, and false if cancel was clicked
+        if (ok) {
+          // determine new "coordinates"
+          let CWidth = gCurrentImageData.C_max.r - gCurrentImageData.C_min.r;
+          let CHeight = gCurrentImageData.C_max.i - gCurrentImageData.C_min.i;
+          let newC_min = new complex(
+              gCurrentImageData.C_min.r + zoomstart.x / gCurrentImageData.iWidth * CWidth,
+              gCurrentImageData.C_min.i + zoomstart.y / gCurrentImageData.iHeight * CHeight);
+          let newC_max = new complex(
+              gCurrentImageData.C_min.r + zoomend.x / gCurrentImageData.iWidth * CWidth,
+              gCurrentImageData.C_min.i + zoomend.y / gCurrentImageData.iHeight * CHeight);
+
+          adjustCoordsAndDraw(newC_min, newC_max);
+        }
       }
       zoomstart = undefined;
     break;
@@ -363,20 +452,19 @@ function mouseevent(etype, event) {
 }
 
 function saveImage() {
-  const bundle = document.getElementById("mbrotBundle");
   const nsIFilePicker = Components.interfaces.nsIFilePicker;
-  var fp = null;
+  let fp = null;
   try {
     fp = Components.classes["@mozilla.org/filepicker;1"]
                    .createInstance(nsIFilePicker);
   } catch (e) {}
   if (!fp) return;
-  var promptString = bundle.getString("savePrompt");
+  let promptString = gMbrotBundle.getString("savePrompt");
   fp.init(window, promptString, nsIFilePicker.modeSave);
-  fp.appendFilter(bundle.getString("pngFilterName"), "*.png");
+  fp.appendFilter(gMbrotBundle.getString("pngFilterName"), "*.png");
   fp.defaultString = "mandelbrot.png";
 
-  var fpResult = fp.show();
+  let fpResult = fp.show();
   if (fpResult != nsIFilePicker.returnCancel) {
     saveCanvas(document.getElementById("mbrotImage"), fp.file);
   }
@@ -387,24 +475,26 @@ function updateBookmarkMenu(aParent) {
     (!document.getElementById("drawButton").hidden || (gStartTime > 0));
 
   while (aParent.hasChildNodes() &&
-         aParent.lastChild.id != 'bookmarkSeparator')
+         aParent.lastChild.id != "bookmarkSeparator")
     aParent.removeChild(aParent.lastChild);
 
-  var file = Components.classes["@mozilla.org/file/directory_service;1"]
+  let file = Components.classes["@mozilla.org/file/directory_service;1"]
                        .getService(Components.interfaces.nsIProperties)
                        .get("ProfD", Components.interfaces.nsIFile);
   file.append("mandelbookmarks.sqlite");
   if (file.exists()) {
-    var connection = Components.classes["@mozilla.org/storage/service;1"]
+    let connection = Components.classes["@mozilla.org/storage/service;1"]
                                .getService(Components.interfaces.mozIStorageService)
                                .openDatabase(file);
     try {
       if (connection.tableExists("bookmarks")) {
-        var statement = connection.createStatement(
-            "SELECT name FROM bookmarks ORDER BY ROWID DESC");
-        while (statement.executeStep())
-          aParent.appendChild(document.createElement("menuitem"))
-                 .setAttribute("label", statement.getString(0));
+        let statement = connection.createStatement(
+            "SELECT name,ROWID FROM bookmarks ORDER BY ROWID ASC");
+        while (statement.executeStep()) {
+          let newItem = aParent.appendChild(document.createElement("menuitem"));
+          newItem.setAttribute("label", statement.getString(0));
+          newItem.setAttribute("bmRowID", statement.getString(1));
+        }
         statement.reset();
         statement.finalize();
         return;
@@ -414,34 +504,67 @@ function updateBookmarkMenu(aParent) {
     }
   }
   // Create the "Nothing Available" Menu item and disable it.
-  var na = aParent.appendChild(document.createElement("menuitem"));
-  na.setAttribute("label",
-                  document.getElementById("mbrotBundle").getString("noBookmarks"));
+  let na = aParent.appendChild(document.createElement("menuitem"));
+  na.setAttribute("label", gMbrotBundle.getString("noBookmarks"));
   na.setAttribute("disabled", "true");
 }
 
 function callBookmark(evtarget) {
+  if (evtarget.id == "bookmarkSave" || evtarget.id == "bookmarkSeparator")
+    return;
+  if (evtarget.id == "bookmarkOverview") {
+    adjustCoordsAndDraw(new complex(0,0), new complex(0,0));
+    return;
+  }
+
+  if (evtarget.getAttribute('bmRowID')) {
+    let iterMax = 0;
+    let C_min = null;
+    let C_max = null;
+
+    let file = Components.classes["@mozilla.org/file/directory_service;1"]
+                         .getService(Components.interfaces.nsIProperties)
+                         .get("ProfD", Components.interfaces.nsIFile);
+    file.append("mandelbookmarks.sqlite");
+    let connection = Components.classes["@mozilla.org/storage/service;1"]
+                               .getService(Components.interfaces.mozIStorageService)
+                               .openDatabase(file);
+    let statement = connection.createStatement(
+        "SELECT iteration_max,Cr_min,Cr_max,Ci_min,Ci_max FROM bookmarks WHERE ROWID=?1");
+    statement.bindStringParameter(0, evtarget.getAttribute('bmRowID'));
+    while (statement.executeStep()) {
+      iterMax = statement.getInt32(0);
+      C_min = new complex(statement.getDouble(1), statement.getDouble(3));
+      C_max = new complex(statement.getDouble(2), statement.getDouble(4));
+    }
+    statement.finalize();
+    connection.close();
+
+    if (iterMax && C_min && C_max) {
+      gPref.setIntPref("mandelbrot.iteration_max", iterMax);
+      adjustCoordsAndDraw(C_min, C_max);
+    }
+  }
 }
 
 function saveBookmark() {
   // retrieve wanted bookmark name with a prompt
-  var mbrotBundle = document.getElementById("mbrotBundle");
-  var prompts = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
+  let prompts = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
                           .getService(Components.interfaces.nsIPromptService);
-  var input = {value: ""}; // empty default value
-  var ok = prompts.prompt(null, "XXX Title", "XXX Please enter a name for the bookmark", input, null, {});
+  let input = {value: ""}; // empty default value
+  let ok = prompts.prompt(null, gMbrotBundle.getString("saveBookmarkTitle"), gMbrotBundle.getString("saveBookmarkLabel"), input, null, {});
   // ok is true if OK is pressed, false if Cancel. input.value holds the value of the edit field if "OK" was pressed.
   if (!ok || !input.value)
     return
 
-  var bmName = input.value;
+  let bmName = input.value;
 
   // Open or create the bookmarks database.
-  var file = Components.classes["@mozilla.org/file/directory_service;1"]
+  let file = Components.classes["@mozilla.org/file/directory_service;1"]
                        .getService(Components.interfaces.nsIProperties)
                        .get("ProfD", Components.interfaces.nsIFile);
   file.append("mandelbookmarks.sqlite");
-  var connection = Components.classes["@mozilla.org/storage/service;1"]
+  let connection = Components.classes["@mozilla.org/storage/service;1"]
                              .getService(Components.interfaces.mozIStorageService)
                              .openDatabase(file);
   connection.beginTransaction();
@@ -453,14 +576,14 @@ function saveBookmark() {
   // TEXT. The value is a text string, stored using the database encoding (UTF-8, UTF-16BE or UTF-16-LE).
 
   // Put value of the current image into the bookmarks table
-  var statement = connection.createStatement(
+  let statement = connection.createStatement(
       "INSERT INTO bookmarks (name,iteration_max,Cr_min,Cr_max,Ci_min,Ci_max) VALUES (?1,?2,?3,?4,?5,?6)");
   statement.bindStringParameter(0, bmName);
-  statement.bindStringParameter(1, gPref.getIntPref("mandelbrot.iteration_max"));
-  statement.bindStringParameter(2, parseFloat(gPref.getCharPref("mandelbrot.last_image.Cr_min")));
-  statement.bindStringParameter(3, parseFloat(gPref.getCharPref("mandelbrot.last_image.Cr_max")));
-  statement.bindStringParameter(4, parseFloat(gPref.getCharPref("mandelbrot.last_image.Ci_min")));
-  statement.bindStringParameter(5, parseFloat(gPref.getCharPref("mandelbrot.last_image.Ci_max")));
+  statement.bindStringParameter(1, gCurrentImageData.iterMax);
+  statement.bindStringParameter(2, gCurrentImageData.C_min.r);
+  statement.bindStringParameter(3, gCurrentImageData.C_max.r);
+  statement.bindStringParameter(4, gCurrentImageData.C_min.i);
+  statement.bindStringParameter(5, gCurrentImageData.C_max.i);
   statement.execute();
   statement.finalize();
   connection.commitTransaction();
@@ -468,19 +591,18 @@ function saveBookmark() {
 }
 
 function updateIterMenu() {
+  let currentIter = 0;
   try {
-    var currentIter = gPref.getIntPref("mandelbrot.iteration_max");
-  }
-  catch(e) {
-    var currentIter = 0;
+    currentIter = gPref.getIntPref("mandelbrot.iteration_max");
   }
+  catch(e) { }
   if (currentIter < 10) {
     currentIter = 500;
     setIter(currentIter);
   }
 
-  var popup = document.getElementById("menu_iterPopup");
-  var item = popup.firstChild;
+  let popup = document.getElementById("menu_iterPopup");
+  let item = popup.firstChild;
   while (item) {
     if (item.getAttribute("name") == "iter") {
       if (item.getAttribute("value") == currentIter)
@@ -497,12 +619,11 @@ function setIter(aIter) {
 }
 
 function updatePaletteMenu() {
+  let currentPalette = '';
   try {
-    var currentPalette = gPref.getCharPref("mandelbrot.color_palette");
-  }
-  catch(e) {
-    var currentPalette = '';
+    currentPalette = gPref.getCharPref("mandelbrot.color_palette");
   }
+  catch(e) { }
   if (!currentPalette.length) {
     currentPalette = 'kairo';
     setPalette(currentPalette);
@@ -510,8 +631,8 @@ function updatePaletteMenu() {
   if (!gColorPalette || !gColorPalette.length)
     gColorPalette = getColorPalette(currentPalette);
 
-  var popup = document.getElementById("menu_palettePopup");
-  var item = popup.firstChild;
+  let popup = document.getElementById("menu_palettePopup");
+  let item = popup.firstChild;
   while (item) {
     if (item.getAttribute("name") == "palette") {
       if (item.getAttribute("value") == currentPalette)
@@ -544,19 +665,18 @@ function toggleJITState(jitMenuItem) {
 }
 
 function updateAlgoMenu() {
+  let currentAlgo = '';
   try {
-    var currentAlgo = gPref.getCharPref("mandelbrot.use_algorithm");
-  }
-  catch(e) {
-    var currentAlgo = '';
+    currentAlgo = gPref.getCharPref("mandelbrot.use_algorithm");
   }
+  catch(e) { }
   if (!currentAlgo.length) {
     currentAlgo = 'numeric';
     setAlgorithm(currentAlgo);
   }
 
-  var popup = document.getElementById("menu_algoPopup");
-  var item = popup.firstChild;
+  let popup = document.getElementById("menu_algoPopup");
+  let item = popup.firstChild;
   while (item) {
     if (item.getAttribute("name") == "algorithm") {
       if (item.getAttribute("value") == currentAlgo)
@@ -573,7 +693,7 @@ function setAlgorithm(algoID) {
 }
 
 function addonsManager(aPane) {
-  var theEM = Components.classes["@mozilla.org/appshell/window-mediator;1"]
+  let theEM = Components.classes["@mozilla.org/appshell/window-mediator;1"]
                         .getService(Components.interfaces.nsIWindowMediator)
                         .getMostRecentWindow("Extension:Manager");
   if (theEM) {