Merge pull request #308 from Tyriar/294_scroll

Implement scrollPages, scrollToTop, scrollToBottom and add scroll tests

test/test.js

@@ -88,6 +88,101 @@ describe('xterm.js', function() {
     });
   });
 
+  describe('scroll', function() {
+    describe('scrollDisp', function() {
+      var startYDisp;
+      beforeEach(function() {
+        for (var i = 0; i < xterm.rows * 2; i++) {
+          xterm.writeln('test');
+        }
+        startYDisp = xterm.rows + 1;
+      });
+      it('should scroll a single line', function() {
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollDisp(-1);
+        assert.equal(xterm.ydisp, startYDisp - 1);
+        xterm.scrollDisp(1);
+        assert.equal(xterm.ydisp, startYDisp);
+      });
+      it('should scroll multiple lines', function() {
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollDisp(-5);
+        assert.equal(xterm.ydisp, startYDisp - 5);
+        xterm.scrollDisp(5);
+        assert.equal(xterm.ydisp, startYDisp);
+      });
+      it('should not scroll beyond the bounds of the buffer', function() {
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollDisp(1);
+        assert.equal(xterm.ydisp, startYDisp);
+        for (var i = 0; i < startYDisp; i++) {
+          xterm.scrollDisp(-1);
+        }
+        assert.equal(xterm.ydisp, 0);
+        xterm.scrollDisp(-1);
+        assert.equal(xterm.ydisp, 0);
+      });
+    });
+
+    describe('scrollPages', function() {
+      var startYDisp;
+      beforeEach(function() {
+        for (var i = 0; i < xterm.rows * 3; i++) {
+          xterm.writeln('test');
+        }
+        startYDisp = (xterm.rows * 2) + 1;
+      });
+      it('should scroll a single page', function() {
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollPages(-1);
+        assert.equal(xterm.ydisp, startYDisp - (xterm.rows - 1));
+        xterm.scrollPages(1);
+        assert.equal(xterm.ydisp, startYDisp);
+      });
+      it('should scroll a multiple pages', function() {
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollPages(-2);
+        assert.equal(xterm.ydisp, startYDisp - (xterm.rows - 1) * 2);
+        xterm.scrollPages(2);
+        assert.equal(xterm.ydisp, startYDisp);
+      });
+    });
+
+    describe('scrollToTop', function() {
+      beforeEach(function() {
+        for (var i = 0; i < xterm.rows * 3; i++) {
+          xterm.writeln('test');
+        }
+      });
+      it('should scroll to the top', function() {
+        assert.notEqual(xterm.ydisp, 0);
+        xterm.scrollToTop();
+        assert.equal(xterm.ydisp, 0);
+      });
+    });
+
+    describe('scrollToBottom', function() {
+      var startYDisp;
+      beforeEach(function() {
+        for (var i = 0; i < xterm.rows * 3; i++) {
+          xterm.writeln('test');
+        }
+        startYDisp = (xterm.rows * 2) + 1;
+      });
+      it('should scroll to the bottom', function() {
+        xterm.scrollDisp(-1);
+        xterm.scrollToBottom();
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollPages(-1);
+        xterm.scrollToBottom();
+        assert.equal(xterm.ydisp, startYDisp);
+        xterm.scrollToTop();
+        xterm.scrollToBottom();
+        assert.equal(xterm.ydisp, startYDisp);
+      });
+    });
+  });
+
   describe('evaluateKeyEscapeSequence', function() {
     it('should return the correct escape sequence for unmodified keys', function() {
       // Backspace