Remove experimental/PdfViewer

experimental/PdfViewer/src/SkTDStackNester.h

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkTDStackNester_DEFINED
-#define SkTDStackNester_DEFINED
-
-#include "SkTypes.h"
-#include "SkPdfReporter.h"
-
-// Adobe limits it to 28. Allow deeper nesting in case a file does not quite meet the
-// spec. 256 should be more than enough.
-#define MAX_NESTING 256
-
-/** \class SkTDStackNester
- *
- * Specialized version of SkTDStack which allows a stack of stacks.
- * FIXME (scroggo): Could this be a subclass of SkTDStack? Could it have-a SkTDStack?
- * The difference between SkTDStackNester and SkTDStack is that:
- *   - SkTDStackNester uses new/delete to manage initializations
- *     FIXME (scroggo): Why use new rather than malloc?
- *   - Supports nest/unnest which simulates a stack of stack. unnest will pop all the
- *     objects pushed since the last nest
- *   - kSlotCount is 64, instead of 8.
- *     FIXME (scroggo): How did we arrive at this number?
- */
-
-template <typename T> class SkTDStackNester : SkNoncopyable {
-public:
-    SkTDStackNester()
-        : fCount(0)
-        , fLocalCount(0)
-        , fNestingLevel(0) {
-        fInitialRec.fNext = NULL;
-        fRec = &fInitialRec;
-        SkDEBUGCODE(fTotalCount = 0;)
-    }
-
-    ~SkTDStackNester() {
-        Rec* rec = fRec;
-        while (rec != &fInitialRec) {
-            Rec* next = rec->fNext;
-            delete rec;
-            rec = next;
-        }
-    }
-
-    /**
-     * Return the number of objects in the current nesting level.
-     */
-    int count() const { return fLocalCount; }
-
-    /**
-     * Whether the current nesting level is empty.
-     */
-    bool empty() const { return fLocalCount == 0; }
-
-    /**
-     * The current nesting level.
-     */
-    int nestingLevel() const {
-        return fNestingLevel;
-    }
-
-    /**
-     * Analogous to an SkCanvas::save(). When unnest() is called, the state of this SkTDStackNester
-     * will return to its state when nest() was called.
-     *
-     * After a call to nest(), fLocalCount is reset to 0, since the stack is on a new nesting
-     * level.
-     */
-    void nest() {
-        SkASSERT(fNestingLevel >= 0);
-        if (fNestingLevel < MAX_NESTING) {
-            fNestings[fNestingLevel] = fLocalCount;
-            fLocalCount = 0;
-        } else {
-            // We are are past max nesting levels. We will still continue to work, but we might fail
-            // to properly ignore errors. Ideally it should only mean poor rendering in exceptional
-            // cases.
-            SkPdfReport(kWarning_SkPdfIssueSeverity, kStackNestingOverflow_SkPdfIssue,
-                        "Past maximum nesting level", NULL, NULL);
-        }
-        fNestingLevel++;
-    }
-
-    /**
-     * Analagous to an SkCanvas::restore(). Will revert this stack to the state it was in the last
-     * time nest() was called. It is an error to call unnest() more times than nest() has been
-     * called.
-     */
-    void unnest() {
-        SkASSERT(fNestingLevel >= 0);
-        if (0 == fNestingLevel) {
-            SkPdfReport(kWarning_SkPdfIssueSeverity, kStackNestingOverflow_SkPdfIssue,
-                        "Nesting underflow", NULL, NULL);
-            return;
-        }
-
-        fNestingLevel--;
-        if (fNestingLevel < MAX_NESTING) {
-            while (fLocalCount > 0) {
-                // FIXME (scroggo): Pass the object?
-                SkPdfReport(kInfo_SkPdfIssueSeverity, kUnusedObject_SkPdfIssue,
-                            "Unused object when calling unnest!", NULL, NULL);
-                this->pop();
-            }
-            fLocalCount = fNestings[fNestingLevel];
-        }
-    }
-
-    /**
-     * Add an object to the stack, and return a pointer to it for modification.
-     */
-    T* push() {
-        SkASSERT(fCount <= kSlotCount);
-        if (fCount == kSlotCount) {
-            Rec* rec = new Rec();
-            rec->fNext = fRec;
-            fRec = rec;
-            fCount = 0;
-        }
-        SkDEBUGCODE(++fTotalCount;)
-        ++fLocalCount;
-        return &fRec->fSlots[fCount++];
-    }
-
-    /**
-     * Add an object to the stack, copied from elem.
-     */
-    void push(const T& elem) { *this->push() = elem; }
-
-    /**
-     * Return the top element.
-     */
-    const T& top() const {
-        SkASSERT(fRec && fCount > 0);
-        return fRec->fSlots[fCount - 1];
-    }
-
-    /**
-     * Return the top element.
-     */
-    T& top() {
-        SkASSERT(fRec && fCount > 0);
-        return fRec->fSlots[fCount - 1];
-    }
-
-    /**
-     * Pop an object off the stack (via pop()), and copy its members into elem.
-     */
-    void pop(T* elem) {
-        if (elem) {
-            *elem = fRec->fSlots[fCount - 1];
-        }
-        this->pop();
-    }
-
-    /**
-     * Pop an object off the stack. It is an error to call pop() more times
-     * than push() has been called in total or since the last call to nest().
-     */
-    void pop() {
-        SkASSERT(fCount > 0 && fRec);
-        SkASSERT(fLocalCount > 0);
-        --fLocalCount;
-        SkDEBUGCODE(--fTotalCount;)
-        if (--fCount == 0) {
-            if (fRec != &fInitialRec) {
-                Rec* rec = fRec->fNext;
-                delete fRec;
-                fCount = kSlotCount;
-                fRec = rec;
-            } else {
-                SkASSERT(fTotalCount == 0);
-            }
-        }
-    }
-
-private:
-    enum {
-        // Number of objects held per Rec. Storing multiple objects in one Rec
-        // means that we call new less often.
-        kSlotCount  = 64
-    };
-
-    struct Rec {
-        Rec* fNext;
-        T    fSlots[kSlotCount];
-    };
-
-    // First Rec, requiring no allocation.
-    Rec     fInitialRec;
-    // The Rec on top of the stack.
-    Rec*    fRec;
-    // Number of objects in fRec.
-    int     fCount;
-    // Number of objects in the current nesting level.
-    int     fLocalCount;
-    // Array of counts of objects per nesting level.
-    // Only valid for fNestings[0] through fNestings[fNestingLevel-1].
-    int     fNestings[MAX_NESTING];
-    // Current nesting level.
-    int     fNestingLevel;
-    // Total number of objects in this SkTDStackNester.
-    SkDEBUGCODE(int     fTotalCount;)
-
-    // For testing.
-    friend class SkTDStackNesterTester;
-};
-#endif // SkTDStackNester_DEFINED