messagegui: further refactoring

Author: thyttan

apps/messagegui/app.js

@@ -250,65 +250,62 @@ function showMusicMessage(msg) {
 function showMessagesScroller(msg, persist, alreadyProcessed) {
   if (persist===undefined) {persist = true;}
   const MSG_IDX = msg ? MESSAGES.findIndex((m)=>m.id==msg.id) : 0;
-  const INITIATED_FROM =
+  const INITIATED_FROM = (
     alreadyProcessed===undefined ? "other function" :
-      (MSG_IDX<=alreadyProcessed.startIdx ? "scrolling up" :
-        (MSG_IDX >= alreadyProcessed.stopIdx-1 ? "scrolling down" : undefined));
+      (MSG_IDX<=alreadyProcessed.idxSpan.start ? "scrolling up" :
+        (MSG_IDX >= alreadyProcessed.idxSpan.stop-1 ? "scrolling down" :
+          undefined))
+  );
+  if (!alreadyProcessed) {alreadyProcessed = {idxSpan:{}};} // So `alreadyProcessed.idxSpan.start/stop` can be looked for on first run.
 
   const WU = require("widget_utils");
   WU.hide();
 
   if (replying) { return; }
   if (persist) {cancelReloadTimeout();} else {resetReloadTimeout();}
 
-  let updatedProcessed = {};
-  let startIdx = 0;
-  let stopIdx = 0;
-
-  if (INITIATED_FROM === "other function") {
-    startIdx = Math.max(MSG_IDX-1, 0);
-    stopIdx = Math.min(MSG_IDX+2, MESSAGES.length);
-    Object.assign(updatedProcessed, {startIdx:startIdx, stopIdx:stopIdx});
-  } else if (INITIATED_FROM === "scrolling up") {
-    startIdx = MSG_IDX;
-    stopIdx = alreadyProcessed.startIdx;
-    Object.assign(updatedProcessed,
-      {startIdx:startIdx, stopIdx:alreadyProcessed.stopIdx});
-  } else if (INITIATED_FROM === "scrolling down") {
-    startIdx = alreadyProcessed.stopIdx;
-    stopIdx = Math.min(MSG_IDX+1, MESSAGES.length);
-    Object.assign(updatedProcessed,
-      {startIdx:alreadyProcessed.startIdx, stopIdx:stopIdx});
-  }
+  let idxSpan = (
+    INITIATED_FROM==="other function" ?
+      {start : Math.max(MSG_IDX-1, 0), stop : Math.min(MSG_IDX+2, MESSAGES.length)} :
+      (INITIATED_FROM==="scrolling up" ?
+        {start : MSG_IDX, stop : alreadyProcessed.idxSpan.start } :
+        (INITIATED_FROM==="scrolling down" ?
+          { start : alreadyProcessed.idxSpan.stop, stop : Math.min(MSG_IDX+1, MESSAGES.length) } :
+          undefined))
+  );
 
   active = "scroller";
   var bodyFont = fontBig;
   g.setFont(bodyFont);
   var titleLines = [];
   var messagesWrapped = [];
-  for (let i=startIdx ; i<stopIdx ; i++) {
+  for (let i=idxSpan.start ; i<idxSpan.stop ; i++) {
     let msgLocal = MESSAGES[i];
     msgLocal.new = false;
 
     if (msgLocal.id=="music" || msgLocal.source=="maps" || msgLocal.id =="call") {
-      stopIdx++
-      if (stopIdx>=MESSAGES.length) {break;}
+      idxSpan.stop++
+      if (idxSpan.stop>=MESSAGES.length) {break;}
       continue;
     }
 
     var lines = [];
-    const TITLE_STRING = "".concat(msgLocal.title, msgLocal.title&&"\n",
-      msgLocal.sender, msgLocal.sender&&"\n", msgLocal.subject,
-      msgLocal.subject&&"\n", msgLocal.src) || "No Title";
+    const TITLE_STRING = msgLocal.title||msgLocal.sender||msgLocal.subject||msgLocal.src||"No Title";
+    //const TITLE_STRING = "".concat(msgLocal.title, msgLocal.title&&"\n",
+    //  msgLocal.sender, msgLocal.sender&&"\n",
+    //  msgLocal.subject, msgLocal.subject&&"\n", msgLocal.src) || "No Title";
     lines = g.wrapString(TITLE_STRING, g.getWidth()-10);
     for (let i=0; i<lines.length; i++) {
       titleLines.push(i + (messagesWrapped[0]?messagesWrapped[0].length:0) +
         (messagesWrapped[1]?messagesWrapped[1].length:0));
     }
     var titleCnt = lines.length;
     if (titleCnt) {lines.push("");} // add blank line after title
+    //const PAD_LEN = (MESSAGES.length-i)/2;
+    //const END_LINE = "-".repeat(PAD_LEN)+"<"+"=".repeat(i)+">"+"-".repeat(PAD_LEN);
+    const END_LINE = "-".repeat(12);
     lines = lines.concat(g.wrapString(msgLocal.body, g.getWidth()-10),
-      ["-".repeat(i+1)]);
+      [END_LINE]);
     messagesWrapped.push(lines);
   }
 
@@ -325,7 +322,7 @@ function showMessagesScroller(msg, persist, alreadyProcessed) {
       map((x) => x + allLines.length));
     allLines = allLines.concat(alreadyProcessed.lines);
   } else if (INITIATED_FROM === "scrolling down") {
-    initScroll = alreadyProcessed.lines.length-9; // FIXME: `-9` corresponds to the Bangle.js 2 screen height - should probably be variable by screen height, font height.
+    initScroll = alreadyProcessed.lines.length-(g.getHeight()/g.getFontHeight());
     titleLines = alreadyProcessed.titleLines.concat(titleLines.
       map((x) => x + alreadyProcessed.lines.length));
     allLines = alreadyProcessed.lines.concat(allLines);
@@ -336,49 +333,55 @@ function showMessagesScroller(msg, persist, alreadyProcessed) {
     returnToClockIfEmpty();
   }
 
-  Object.assign(updatedProcessed,
-    { lines : allLines,
-      titleLines : titleLines,
-      messagesWrappedLength : messagesWrapped.length });
+  alreadyProcessed = { // Update with the newly processed messages.
+    lines : allLines,
+    titleLines : titleLines,
+    idxSpan: {
+      start : Math.min(idxSpan.start, alreadyProcessed.idxSpan.start||MESSAGES.length),
+      stop : Math.max(idxSpan.stop, alreadyProcessed.idxSpan.stop||0)}
+  };
 
-  let prevScrollIdx; // Used for stopping multiple triggers of next message by the scroller.
+  let prevScrollIdx; // Used for stopping repeated triggering of next message by the scroller.
 
   E.showScroller({
     scroll : initScroll*g.getFontHeight(),
     h : g.getFontHeight(), // height of each menu item in pixels
     c : allLines.length, // number of menu items
     // a function to draw a menu item
     draw : function(scrollIdx, r) {
-      "ram"
-      g.setBgColor(titleLines.find((e)=>e==scrollIdx)!==undefined ? g.theme.bg2 : g.theme.bg).
-        setColor(titleLines.find((e)=>e==scrollIdx)!==undefined ? g.theme.fg2 : g.theme.fg).
+      "ram";
+      g.setBgColor(titleLines.find(e=>e==scrollIdx)!==undefined ? g.theme.bg2 : g.theme.bg).
+        setColor(titleLines.find(e=>e==scrollIdx)!==undefined ? g.theme.fg2 : g.theme.fg).
         clearRect(r);
       g.setFont(bodyFont).setFontAlign(0,-1).drawString(allLines[scrollIdx], r.x+r.w/2, r.y);
       // Load in next/previous message on demand by reinitializing showMessagesScroller while passing on the processed messages.
       if (scrollIdx>=allLines.length-1 && scrollIdx!=prevScrollIdx &&
-        updatedProcessed.stopIdx<MESSAGES.length) {
+        alreadyProcessed.idxSpan.stop<MESSAGES.length) {
         setTimeout(() => {
           E.showScroller();
-          showMessagesScroller(MESSAGES[updatedProcessed.stopIdx], true, updatedProcessed);
+          showMessagesScroller(MESSAGES[alreadyProcessed.idxSpan.stop],
+            true, alreadyProcessed);
         }, 40);
       }
-      if (scrollIdx==0 && scrollIdx!=prevScrollIdx && updatedProcessed.startIdx>0) {
+      if (scrollIdx==0 && scrollIdx!=prevScrollIdx && alreadyProcessed.idxSpan.start>0) {
         setTimeout(() => {
           E.showScroller();
-          showMessagesScroller(MESSAGES[updatedProcessed.startIdx-1], true, updatedProcessed);
+          showMessagesScroller(MESSAGES[alreadyProcessed.idxSpan.start-1],
+            true, alreadyProcessed);
         }, 40);
       }
       prevScrollIdx = scrollIdx;
-    }, select : function(scrollIdx, touch) {
+    },
+    select : function(scrollIdx, touch) {
       let msgSelect;
-      let titleLinesInitials = [titleLines[0]];
+      let firstTitleLinePerMsg = [titleLines[0]];
       for (let i=1; i<titleLines.length; i++) {
         if (titleLines[i]-titleLines[i-1] === 1) {continue;}
-        titleLinesInitials.push(titleLines[i]);
+        firstTitleLinePerMsg.push(titleLines[i]);
       }
       for (let i=titleLines.length-1; i>=0 ; i--) {
-        if (scrollIdx>=titleLinesInitials[i]) {
-          msgSelect = MESSAGES[i + updatedProcessed.startIdx];
+        if (scrollIdx>=firstTitleLinePerMsg[i]) {
+          msgSelect = MESSAGES[i + alreadyProcessed.idxSpan.start];
           break;
         }
       }