Add slider to enable distant paging.

[quanweb.git] / app / lib.js

diff --git a/app/lib.js b/app/lib.js
index 5e2ecf830b6ec52330446cf61f0dae3dd6ca06d8..50086d0db6c12fda13f253e31f41edbf7489a164 100644 (file)
--- a/app/lib.js
+++ b/app/lib.js
@@ -7,7 +7,33 @@ g_state = {
   first: 0,
   ids: [],
   last: (-1),
-  pageSize: 100
+  pageSize: 9
+}
+
+function adjustPos(setting) {
+  var value = parseInt(setting)
+  
+  if (g_state.first === value) {
+    // No change
+    return;
+  }
+
+  var maxFirst = g_state.count - g_state.pageSize;
+
+  if (value < 0) {
+    g_state.first = 0;
+  } else if (value > maxFirst) {
+    g_state.first = maxFirst;
+  } else {
+    g_state.first = value;
+  }
+
+  g_state.last = g_state.first + g_state.pageSize - 1;
+  if (g_state.last >= g_state.count) {
+    g_state.last = g_state.count - 1;
+  }
+
+  refreshData();
 }
 
 function constructSearchUrl() {
@@ -42,28 +68,20 @@ function constructSearchUrl() {
 
 function onNext() {
   if (g_state.last < (g_state.count - 1)) {
-    g_state.first += g_state.pageSize;
-    g_state.last += g_state.pageSize;
-    if (g_state.last >= g_state.count) {
-      g_state.last = g_state.count - 1;
-    }
-
-    refreshData();
+    adjustPos(g_state.first + g_state.pageSize);
   }
 }
 
 function onPrev() {
   if (g_state.first > 0) {
-    g_state.first -= g_state.pageSize;
-    if (g_state.first < 0) {
-      g_state.first = 0;
-    }
-    g_state.last = g_state.first + g_state.pageSize;
-    
-    refreshData();
+    adjustPos(g_state.first - g_state.pageSize);
   }
 }
 
+function onSlide(value) {
+  adjustPos(value);
+}
+
 function onSearch() {
   console.log('onSearch()');
 
@@ -78,12 +96,13 @@ function onSearch() {
     console.log('JSON response:  ', jsonValue);
     g_state.ids = jsonValue
     g_state.count = g_state.ids.length;
-    g_state.first = 0
-    g_state.last = (g_state.ids.length) - 1;
-    if (g_state.last > g_state.pageSize) {
-      g_state.last = g_state.pageSize;
-    }
-    refreshData()
+    g_state.first = (-1)
+
+    var elem = document.getElementById('slider');
+    elem.max = g_state.count;
+    elem.value = '0'
+
+    adjustPos(0);
   })
   .catch(err => { 
     var msg = 'Error fetching JSON from URL:  ' + url + ': ' + err + ':' + err.stack;