Accept resolution or zoom related options for constrained views

Any of minResolution, maxResolution, minZoom, or maxZoom can be used to constrain the view resolutions. Resolution options are given precedence over zoom options.
2014-05-15 16:43:27 -06:00
parent 3384ba07e3
commit 815f5b38c8
3 changed files with 269 additions and 28 deletions
@@ -58,6 +58,185 @@ describe('ol.View2D', function() {
        });
      });

+      describe('with zoom related options', function() {
+
+        var defaultMaxRes = 156543.03392804097;
+        function getConstraint(options) {
+          return ol.View2D.createResolutionConstraint_(options).constraint;
+        }
+
+        it('works with only maxZoom', function() {
+          var maxZoom = 10;
+          var constraint = getConstraint({
+            maxZoom: maxZoom
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes, 1e-9);
+
+          expect(constraint(0, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(2, maxZoom), 1e-9);
+        });
+
+        it('works with only minZoom', function() {
+          var minZoom = 5;
+          var constraint = getConstraint({
+            minZoom: minZoom
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(2, minZoom), 1e-9);
+
+          expect(constraint(0, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(2, 28), 1e-9);
+        });
+
+        it('works with maxZoom and minZoom', function() {
+          var minZoom = 2;
+          var maxZoom = 11;
+          var constraint = getConstraint({
+            minZoom: minZoom,
+            maxZoom: maxZoom
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(2, minZoom), 1e-9);
+
+          expect(constraint(0, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(2, maxZoom), 1e-9);
+        });
+
+        it('works with maxZoom, minZoom, and zoomFactor', function() {
+          var minZoom = 4;
+          var maxZoom = 8;
+          var zoomFactor = 3;
+          var constraint = getConstraint({
+            minZoom: minZoom,
+            maxZoom: maxZoom,
+            zoomFactor: zoomFactor
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(zoomFactor, minZoom), 1e-9);
+
+          expect(constraint(0, 0, 0)).to.roughlyEqual(
+              defaultMaxRes / Math.pow(zoomFactor, maxZoom), 1e-9);
+        });
+
+      });
+
+      describe('with resolution related options', function() {
+
+        var defaultMaxRes = 156543.03392804097;
+        function getConstraint(options) {
+          return ol.View2D.createResolutionConstraint_(options).constraint;
+        }
+
+        it('works with only maxResolution', function() {
+          var maxResolution = 10e6;
+          var constraint = getConstraint({
+            maxResolution: maxResolution
+          });
+
+          expect(constraint(maxResolution * 3, 0, 0)).to.roughlyEqual(
+              maxResolution, 1e-9);
+
+          var minResolution = constraint(0, 0, 0);
+          var defaultMinRes = defaultMaxRes / Math.pow(2, 28);
+
+          expect(minResolution).to.be.greaterThan(defaultMinRes);
+          expect(minResolution / defaultMinRes).to.be.lessThan(2);
+        });
+
+        it('works with only minResolution', function() {
+          var minResolution = 100;
+          var constraint = getConstraint({
+            minResolution: minResolution
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes, 1e-9);
+
+          var constrainedMinRes = constraint(0, 0, 0);
+          expect(constrainedMinRes).to.be.greaterThan(minResolution);
+          expect(constrainedMinRes / minResolution).to.be.lessThan(2);
+        });
+
+        it('works with minResolution and maxResolution', function() {
+          var constraint = getConstraint({
+            maxResolution: 500,
+            minResolution: 100
+          });
+
+          expect(constraint(600, 0, 0)).to.be(500);
+          expect(constraint(500, 0, 0)).to.be(500);
+          expect(constraint(400, 0, 0)).to.be(500);
+          expect(constraint(300, 0, 0)).to.be(250);
+          expect(constraint(200, 0, 0)).to.be(250);
+          expect(constraint(100, 0, 0)).to.be(125);
+          expect(constraint(0, 0, 0)).to.be(125);
+        });
+
+        it('accepts minResolution, maxResolution, and zoomFactor', function() {
+          var constraint = getConstraint({
+            maxResolution: 500,
+            minResolution: 1,
+            zoomFactor: 10
+          });
+
+          expect(constraint(1000, 0, 0)).to.be(500);
+          expect(constraint(500, 0, 0)).to.be(500);
+          expect(constraint(100, 0, 0)).to.be(50);
+          expect(constraint(50, 0, 0)).to.be(50);
+          expect(constraint(10, 0, 0)).to.be(5);
+          expect(constraint(1, 0, 0)).to.be(5);
+        });
+
+      });
+
+      describe('overspecified options (prefers resolution)', function() {
+
+        var defaultMaxRes = 156543.03392804097;
+        function getConstraint(options) {
+          return ol.View2D.createResolutionConstraint_(options).constraint;
+        }
+
+        it('respects maxResolution over minZoom', function() {
+          var maxResolution = 10e6;
+          var minZoom = 8;
+          var constraint = getConstraint({
+            maxResolution: maxResolution,
+            minZoom: minZoom
+          });
+
+          expect(constraint(maxResolution * 3, 0, 0)).to.roughlyEqual(
+              maxResolution, 1e-9);
+
+          var minResolution = constraint(0, 0, 0);
+          var defaultMinRes = defaultMaxRes / Math.pow(2, 28);
+
+          expect(minResolution).to.be.greaterThan(defaultMinRes);
+          expect(minResolution / defaultMinRes).to.be.lessThan(2);
+        });
+
+        it('respects minResolution over maxZoom', function() {
+          var minResolution = 100;
+          var maxZoom = 50;
+          var constraint = getConstraint({
+            minResolution: minResolution,
+            maxZoom: maxZoom
+          });
+
+          expect(constraint(defaultMaxRes, 0, 0)).to.roughlyEqual(
+              defaultMaxRes, 1e-9);
+
+          var constrainedMinRes = constraint(0, 0, 0);
+          expect(constrainedMinRes).to.be.greaterThan(minResolution);
+          expect(constrainedMinRes / minResolution).to.be.lessThan(2);
+        });
+
+      });
+
    });

    describe('create rotation constraint', function() {