Add diff and texthistory

modules/gin/gin.cpp

@@ -37,11 +37,16 @@
 
 #include "gin.h"
 
+JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wshorten-64-to-32")
+#include "3rdparty/diff/diff_match_patch.h"
+JUCE_END_IGNORE_WARNINGS_GCC_LIKE
+
 //==============================================================================
 
 namespace gin
 {
-
+#include "utilities/gin_diff.cpp"
+#include "utilities/gin_texthistory.cpp"
 #include "utilities/gin_downloadmanager.cpp"
 #include "utilities/gin_filesystemwatcher.cpp"
 #include "utilities/gin_fileutilities.cpp"

modules/gin/gin.h

@@ -68,6 +68,8 @@
 
 namespace gin
 {
+#include "utilities/gin_diff.h"
+#include "utilities/gin_texthistory.h"
 #include "utilities/gin_point.h"
 #include "utilities/gin_downloadmanager.h"
 #include "utilities/gin_equationparser.h"

modules/gin/utilities/gin_diff.cpp

@@ -0,0 +1,36 @@
+class Diff::Impl
+{
+public:
+    diff_match_patch<std::string> dmp;
+};
+
+Diff::Diff()
+{
+    impl = std::make_unique<Impl>();
+}
+
+Diff::~Diff()
+{
+}
+
+juce::String Diff::diff (const juce::String s1, const juce::String s2)
+{
+    auto diffs = impl->dmp.diff_main (s1.toStdString(), s2.toStdString());
+    auto patches = impl->dmp.patch_make (diffs);
+    return impl->dmp.patch_toText (patches);
+}
+
+juce::String Diff::applyPatch (const juce::String s, const juce::String patchText)
+{
+    auto patches = impl->dmp.patch_fromText (patchText.toStdString());
+    auto [res, status] = impl->dmp.patch_apply (patches, s.toStdString());
+
+    for (auto b : status)
+    {
+        jassert (b);
+        if (! b)
+            return {};
+    }
+
+    return res;
+}

modules/gin/utilities/gin_diff.h

@@ -0,0 +1,15 @@
+#pragma once
+
+class Diff
+{
+public:
+    Diff();
+    ~Diff();
+
+    juce::String diff (const juce::String s1, const juce::String s2);
+    juce::String applyPatch (const juce::String s, const juce::String patch);
+
+private:
+    class Impl;
+    std::unique_ptr<Impl> impl;
+};

modules/gin/utilities/gin_texthistory.cpp

@@ -0,0 +1,59 @@
+
+void TextHistory::addText (const juce::String& t)
+{
+    if (t == currentText)
+        return;
+
+    while (historyStack.size() - 1 > stackPointer)
+        historyStack.removeLast();
+
+    auto fordardPatch = diff.diff (currentText, t);
+    auto backwardPatch = diff.diff (t, currentText);
+
+    historyStack.add ({fordardPatch, backwardPatch});
+    currentText = t;
+
+    while (historyStack.size() > limit)
+    {
+        historyStack.remove (0);
+        stackPointer--;
+    }
+}
+
+const juce::String& TextHistory::getCurrentText()
+{
+    return currentText;
+}
+
+void TextHistory::undo()
+{
+    if (canUndo())
+    {
+        currentText = diff.applyPatch (currentText, historyStack[stackPointer].backwardPatch);
+        stackPointer--;
+    }
+}
+
+void TextHistory::redo()
+{
+    if (canRedo())
+    {
+        currentText = diff.applyPatch (currentText, historyStack[stackPointer + 1].forwardPatch);
+        stackPointer++;
+    }
+}
+
+bool TextHistory::canUndo()
+{
+    return stackPointer > 0;
+}
+
+bool TextHistory::canRedo()
+{
+    return stackPointer < historyStack.size() - 1;
+}
+
+void TextHistory::setHistoryLimit (int limit_)
+{
+    limit = limit_;
+}

modules/gin/utilities/gin_texthistory.h

@@ -0,0 +1,32 @@
+#pragma once
+
+class TextHistory
+{
+public:
+	void setHistoryLimit (int numItems);
+
+	void undo();
+	void redo();
+	bool canUndo();
+	bool canRedo();
+
+    void addText (const juce::String&);
+    const juce::String& getCurrentText();
+
+private:
+	juce::String currentText;
+
+	struct HistoryItem
+	{
+        juce::String forwardPatch;
+        juce::String backwardPatch;
+	};
+
+    Diff diff;
+
+	juce::Array<HistoryItem> historyStack;
+	int stackPointer = -1;
+	int limit = 100;
+};
+//-------------------------------------------------------------------------------------------------
+

modules/gin_plugin/components/gin_plugineditor.h

@@ -177,7 +177,6 @@ class TitleBar : public juce::Component,
     void setShowInfo (bool);
     void setBrowseButtonState (bool s) { browseButton.setToggleState (s, juce::dontSendNotification); }
 
-protected:
     void paint (juce::Graphics& g) override;
     void resized() override;
 

modules/gin_plugin/plugin/gin_processor.cpp

@@ -493,7 +493,7 @@ juce::File Processor::getProgramDirectory()
 
 //==============================================================================
 
-void Processor::getStateInformation (juce::MemoryBlock& destData)
+juce::String Processor::getStateXml()
 {
     updateState();
 
@@ -519,16 +519,27 @@ void Processor::getStateInformation (juce::MemoryBlock& destData)
         }
     }
 
+    return rootE->toString();
+}
+
+void Processor::getStateInformation (juce::MemoryBlock& destData)
+{
+    auto text = getStateXml();
+
     juce::MemoryOutputStream os (destData, true);
-    auto text = rootE->toString();
     os.write (text.toRawUTF8(), text.getNumBytesAsUTF8());
 }
 
 void Processor::setStateInformation (const void* data, int sizeInBytes)
+{
+    setStateXml (juce::String::fromUTF8 ((const char*)data, sizeInBytes));
+}
+
+void Processor::setStateXml (const juce::String& s)
 {
     juce::ScopedValueSetter<bool> (loadingState, true);
 
-    juce::XmlDocument doc (juce::String::fromUTF8 ((const char*)data, sizeInBytes));
+    juce::XmlDocument doc (s);
     std::unique_ptr<juce::XmlElement> rootE (doc.getDocumentElement());
     if (rootE)
     {

modules/gin_plugin/plugin/gin_processor.h

@@ -177,6 +177,9 @@ class Processor : public ProcessorBaseClass,
     bool hasProgram (juce::String name);
 
     //==============================================================================
+    juce::String getStateXml();
+    void setStateXml (const juce::String& s);
+
     void getStateInformation (juce::MemoryBlock& destData) override;
     void setStateInformation (const void* data, int sizeInBytes) override;