Change BrowsingHistory to behave like window.history

src/BrowsingHistory.cpp

@@ -1,33 +1,52 @@
 #include "BrowsingHistory.h"
 
-BrowsingHistory::BrowsingHistory() :
+BrowsingHistory::BrowsingHistory(std::function<void(URL const&)> onGotoPage_) :
     history(),
-    currentPosition(0) {}
+    currentPosition(history.end()),
+    onGotoPage(onGotoPage_) {}
 
-void BrowsingHistory::addEntry(URL url) {
-    if (!history.empty()) {
-        ++currentPosition;
-    }
-    if (currentPosition < history.size()) {
-        history.erase(history.begin() + currentPosition, history.end());
-    }
-    history.push_back(url);
+unsigned int BrowsingHistory::length() const {
+    return history.size();
+}
+
+void BrowsingHistory::back() {
+    go(-1);
+}
+
+void BrowsingHistory::forward() {
+    go(1);
+}
+
+void BrowsingHistory::go() {
+    go(0);
 }
 
-URL const& BrowsingHistory::goForward() {
-    if (currentPosition < history.size()) {
-        ++currentPosition;
+void BrowsingHistory::go(int diff) {
+    if (history.size() == 0) {
+        return;
+    }
+    std::vector<URL>::iterator newPos = currentPosition + diff;
+    if (newPos >= history.begin() && newPos < history.end()) {
+        currentPosition = newPos;
+        onGotoPage(*currentPosition);
     }
-    return history[currentPosition];
 }
 
-URL const& BrowsingHistory::goBack() {
-    if (currentPosition > 0) {
-        --currentPosition;
+void BrowsingHistory::pushState(void* stateObj, std::string const& title, URL const& url) {
+    if (history.size() == 0) {
+        history.push_back(url);
+        currentPosition = history.begin();
+        return;
     }
-    return history[currentPosition];
+    URL currentURL = *currentPosition;
+    history.erase(++currentPosition, history.end());
+    history.push_back(currentURL.merge(url));
+    currentPosition = history.end() - 1;
 }
 
-std::vector<URL> const& BrowsingHistory::getHistory() const {
-    return history;
+void BrowsingHistory::replaceState(void* stateObj, std::string const& title, URL const& url) {
+    if (history.size() == 0) {
+        return;
+    }
+    *currentPosition = (*currentPosition).merge(url);
 }

src/BrowsingHistory.h

@@ -3,20 +3,39 @@
 
 #include <vector>
 #include "URL.h"
+#include <functional>
 
-// if it's going to have fwd/back then
-// please model after https://developer.mozilla.org/en-US/docs/Web/API/History
+/*
+  NOTE: The first parameter of the constructor is the callback to be called when
+        calling go(int) (or back or forward or whatever). Should be a
+        function that navigates to the specified URL.
+ */
+
+// modelled after https://developer.mozilla.org/en-US/docs/Web/API/History
 class BrowsingHistory {
 public:
-    BrowsingHistory();
-    void addEntry(URL url);
-    URL const& goForward();
-    URL const& goBack();
-    std::vector<URL> const& getHistory() const;
+    BrowsingHistory(std::function<void(URL const&)> onGotoPage_);
+
+    unsigned int length() const;
+    //void scrollRestoration(); // TODO: Implement this when it's relevant
+    //void* state() const; // TODO: Implement when we have Javascript objects.
+    
+    void back();
+    void forward();
+    void go();
+    void go(int diff);
+
+    // stateObj: void* should be a Javascript object once we have those. Just
+    //           give it nullptr for the time being.
+    // title: "Firefox currently ignores this parameter, although it may
+    //         use it in the future.". So i guess we ignore it too?
+    void pushState(void* stateObj, std::string const& title, URL const& url);
+    void replaceState(void* stateObj, std::string const& title, URL const& url);
     
 private:
     std::vector<URL> history;
-    unsigned int currentPosition;
+    std::vector<URL>::iterator currentPosition;
+    std::function<void(URL const&)> onGotoPage;
 };
 
 #endif